JP2010036130A - Method and apparatus for recovering water-soluble organic solvent having amino group - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for recovering a water-soluble organic solvent having an amino group such as MEA capable of efficiently recovering the organic solvent from water containing it. <P>SOLUTION: The method comprises a process in which the water containing the water-soluble organic solvent (the water to be treated) is introduced into a mixing/adsorbing tank 1 along with an H-type cation exchange resin from a cation exchange resin tank 4 and stirred to make the solvent exchanged and adsorbed by the cation exchange resin. Then, the cation exchange resin in the mixing/adsorbing tank 1 is introduced into a separating/regenerating tank 2 along with an acid from a regenerant tank 6 to elate the organic solvent and to regenerate the cation exchange resin. The eluted liquid is drawn out to recover the organic solvent while the regenerated H-type cation exchange resin is returned to the cation exchange resin tank 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for recovering a water-soluble organic solvent having an amino group. The present invention preferably uses a water-soluble organic solvent having an amino group from washing wastewater containing a water-soluble organic solvent from a photolithography step in the production of a semiconductor element, a semiconductor substrate, a liquid crystal panel, a plasma display panel, or the like. The present invention relates to a method and apparatus for separating and recovering as a product.

  In recent years, MEA (monoethanolamine), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone) and the like have been used as resist stripping solutions in liquid crystal panel manufacturing processes and semiconductor manufacturing processes. For example, in order to peel and wash a photoresist material, washing water containing dimethyl sulfoxide or the like as an organic solvent is used in addition to ethanolamines as a water-soluble organic solvent having a basic amino group. A large amount of water-soluble organic solvent-containing wastewater is generated from such a peeling / cleaning process, and development of a separation and recovery technique for recycling the organic solvent is desired from the viewpoint of reducing the environmental load.

As described in JP-A-2003-71489, conventionally, waste water containing a water-soluble organic solvent discharged when rinsing a wafer or a liquid crystal panel after resist stripping with ultrapure water is usually activated sludge. Processes such as decomposition and mineralization are applied by general microbial treatments such as the method and biofilm method, or they are incinerated after being concentrated and reduced by an evaporative distillation apparatus. Concentration by evaporative distillation consumes a large amount of energy in association with heating, and the concentrated water-soluble organic solvent-containing wastewater contains a resist component, so that recycling to raw materials is difficult.
JP 2003-71489 A

  The present invention solves the above-mentioned conventional problems and is a water-soluble organic solvent having an amino group that can efficiently recover the water-soluble organic solvent from water-containing organic solvent-containing water having an amino group such as MEA. An object is to provide a recovery method and apparatus.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 1 is a method for recovering the water-soluble organic solvent from water-containing organic solvent-containing water having an amino group. The water-soluble organic solvent is contacted with the cation exchange resin, the water-soluble organic solvent is exchanged and adsorbed on the cation exchange resin, and the water-soluble organic solvent is eluted from the cation exchange resin and recovered.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 2 is the method according to claim 1, wherein water-soluble organic solvent-containing water and H-type cation exchange resin are mixed and the water-soluble organic solvent is exchanged and adsorbed on the cation exchange resin. It is characterized by making it.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 3 is the method according to claim 2, wherein the water-soluble organic solvent-containing water is drainage from a photolithography process and contains monoethanolamine and a photoresist residue. After mixing the water-containing organic solvent-containing water and the H-type cation exchange resin, the H-type cation exchange resin adsorbing the water-soluble organic solvent is separated from the mixed solution, and the separated H-type cation exchange resin is separated. The water-soluble organic solvent is eluted from the water.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 4 is the method according to claim 3, wherein the H-type cation exchange resin is mixed with water-containing organic solvent-containing water so that the pH of the liquid mixture is 6-7. It is characterized by mixing.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 5 is characterized in that, in any one of claims 1 to 4, the water-soluble organic solvent is eluted from the cation exchange resin with an acid. .

  The method for recovering a water-soluble organic solvent having an amino group according to claim 6 is the method according to claim 5, wherein the water-soluble organic solvent eluted from the cation exchange resin is contacted with the anion exchange resin to remove the anion by ion exchange. It is a feature.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 7 is characterized in that, in any one of claims 1 to 4, the water-soluble organic solvent is eluted from the cation exchange resin with an alkali. .

  The method for recovering a water-soluble organic solvent having an amino group according to claim 8 is characterized in that, in any one of claims 1 to 4, the water-soluble organic solvent is eluted from the cation exchange resin with the organic solvent. is there.

  The method for recovering a water-soluble organic solvent having an amino group according to claim 9 is the method according to any one of claims 1 to 8, wherein the cation exchange resin adsorbing the water-soluble organic solvent is washed with water and then the water-soluble organic solvent is eluted. It is characterized by making it.

  The apparatus for recovering a water-soluble organic solvent having an amino group according to claim 10 is an apparatus for recovering a water-soluble organic solvent having an amino group from water-containing organic solvent-containing water having an amino group, the water-soluble organic solvent containing Mixing means for mixing water and H-type cation exchange resin, separation means for separating the water-soluble organic solvent adsorption cation exchange resin from the mixed solution of the mixing means, and elution with the separated water-soluble organic solvent adsorption cation exchange resin And an elution means for elution of the water-soluble organic solvent by contacting with the liquid.

  The water-soluble organic solvent-recovering device having an amino group according to claim 11 comprises the water-washing means for washing the water-soluble organic solvent-adsorbing cation exchange resin separated by the separation means according to claim 10, and the water-washing means. The water-soluble organic solvent is eluted from the water-soluble organic solvent-adsorbing cation exchange resin washed with water by the elution means.

  An apparatus for recovering a water-soluble organic solvent having an amino group according to claim 12 is the apparatus according to claim 10 or 11, wherein the anion exchange means for removing anions from the liquid eluted by the elution means, and the liquid from the anion exchange means are concentrated. And a concentration means.

  According to the present invention, when the water-containing organic solvent-containing water having an amino group comes into contact with the H-type cation exchange resin, the water-soluble organic solvent is exchanged and adsorbed on the cation exchange resin, and the water-soluble organic solvent is removed from the cation exchange resin. Is eluted and recovered.

  In order to bring the water-soluble organic solvent-containing water into contact with the H-type cation exchange resin, it is preferable to mix the water-soluble organic solvent-containing water and the H-type cation exchange resin. This is because water-soluble organic solvent-containing water such as resist waste liquid may contain film-like solids, and when water-soluble organic solvent-containing water is passed through a fixed-bed cation exchange resin bed, This is because the cation exchange resin bed may be clogged (clogged).

  By separating the water-soluble organic solvent-adsorbing cation exchange resin from a mixture of water-soluble organic solvent-containing water and H-type cation exchange resin and eluting the water-soluble organic solvent from the water-soluble organic solvent-adsorbing cation exchange resin The water-soluble organic solvent can be recovered.

  The resist waste liquid is often alkaline with a pH of about 8-10. When mixing water-soluble organic solvent-containing water such as this resist waste liquid and H-type cation exchange resin, the amount of H-type cation exchange resin is such that the pH of the liquid after mixing is about 6-7. Is preferred. This is because when the pH of this solution becomes lower than 6, the dissolved photoresist residue may be precipitated.

  As an eluent for eluting the water-soluble organic solvent from the water-soluble organic solvent-adsorbing cation exchange resin, an acid, an alkali, or an organic solvent can be used.

  When the water-soluble organic solvent is recovered by eluting with an acid and the recovered water-soluble organic solvent-containing water (for example, MEA) is reused as boiler chemicals, it is neutralized with an alkali or the acid component is removed with an anion exchange resin. Therefore, boiler corrosion can be prevented.

  In addition, by washing the cation exchange resin with water prior to elution, it is possible to prevent contamination of the photoresist residue and recover a highly pure water-soluble organic solvent.

  Hereinafter, the present invention will be described in more detail.

  In the present invention, examples of the water-soluble organic solvent having an amino group include monoethanolamine (MEA), diethanolamine, triethanolamine, methylamine, dimethylamine, trimethylamine, hexamethylenediamine, ethylenediamine, and amino acids. In particular, MEA is preferred.

  The present invention is suitable for application to recovering a water-soluble organic solvent having an amino group from wastewater from a photolithography process in the manufacture of semiconductor elements, semiconductor substrates, liquid crystal panels, plasma display panels, and the like. This lithography process wastewater usually contains about 0.1 to 2 g / L of MEA derived from a resist stripping solution and about 0.1 to 2.5 g / L of dimethyl sulfoxide (DMSO). Further, N-methylpyrrolidone may be contained in an amount of about 0.1 to 1 g / L. Moreover, this waste water contains about 0.01 to 1 g / L of photoresist residue. The pH of this waste water is usually about 7-9.

  In the present invention, the water-containing organic solvent-containing water having an amino group is brought into contact with the H-type cation exchange resin, and the water-soluble organic solvent is exchanged and adsorbed on the H-type cation exchange resin. As described above, the drainage from the photolithography process may contain a film-like solid content, and the fixed bed is likely to be blocked when it passes through the fixed bed type cation exchange resin. Therefore, in the present invention, it is preferable to mix the water-soluble organic solvent-containing water and the H-type cation exchange resin for exchange adsorption. The mixing ratio of the H-type cation exchange resin is such that the pH of the mixed liquid (which may be a liquid obtained by separating (for example, filtering) the cation exchange resin from the mixed liquid) is 6 to 7 neutral. A mixing ratio of This is because when an H-form cation exchange resin is added excessively so that the pH is lower than 6, a water-soluble organic solvent having an amino group is precipitated.

  As an eluent for eluting the water-soluble organic solvent from the cation exchange resin exchange-adsorbed with the water-soluble organic solvent, an acid or an organic solvent can be used.

  As the acid, hydrochloric acid, sulfuric acid and the like are preferable, and it is preferable to use as an aqueous solution having a concentration of about 1 to 10 wt%. When the water-soluble organic solvent is eluted with an acid, the cation exchange resin is regenerated into an H-form cation exchange resin with this acid.

  As the alkali, sodium hydroxide is preferable, and it is preferable to use it as an aqueous solution having a concentration of about 1 to 10 wt%. With the alkali, the water-soluble organic solvent adsorbed on the cation exchange resin can be eluted.

  As the organic solvent, alcohol, ether, ester, ketone, aromatic hydrocarbon, chlorinated hydrocarbon, or the like can be used. The optimum extraction solvent varies depending on the type of water-soluble organic solvent having an amino group, and is not limited thereto.

  When the recovered MEA is reused as boiler chemicals (boiler oxygen absorber), it is not preferable that the acid component remains in the MEA because the acid component causes corrosion of the boiler. When MEA is recovered from an acid from a cation exchange resin, an acid component is contained in the MEA aqueous solution. Therefore, it is necessary to remove it using an anion exchange resin or the like or neutralize it by adding an alkali. Since it is better for the boiler feedwater to contain no impurities as much as possible, it is preferable to perform the removal using an anion exchange resin.

  If DMSO is contained in the oxygen scavenger for the boiler, the sulfur content of DMSO is oxidized and sulfuric acid is generated, causing corrosion of the boiler and piping. Therefore, the DMSO concentration in the recovered MEA is as low as possible. It is desirable.

  The water-soluble organic solvent eluted from the cation exchange resin is concentrated by evaporation or the like, if necessary, and recovered as a water-soluble organic solvent or a concentrated liquid thereof.

  The flow of the method and apparatus for recovering a water-soluble organic solvent having an amino group according to the present invention will be described below with reference to FIG.

The water-soluble organic solvent recovery device in FIG. 1 is configured to recover a water-soluble organic solvent as follows.
(1) Water-soluble organic solvent-containing water (liquid to be treated) is introduced into the mixing / adsorption tank 1, and H-type cation exchange resin is introduced into the mixing / adsorption tank 1 from the cation exchange resin storage tank 4 and stirred. A water-soluble organic solvent is exchange-adsorbed on the H-form cation exchange resin.
(2) The cation exchange resin in the mixing / adsorption tank 1 is introduced into the separation / regeneration tank 2 and the liquid to be treated and the cation exchange resin are solid-liquid separated, and then the acid in the regenerant storage tank 6 is transferred to the separation / regeneration tank 2. Introducing, elution of water-soluble organic solvent and regeneration of cation exchange resin.
(3) Remove the eluted liquid (MEA-containing water in this embodiment).
(4) The regenerated H-type cation exchange resin is returned from the separation / regeneration tank 2 to the storage tank 4.

In order to introduce the water-soluble organic solvent-containing water of (1) above, the treated water introduction line L ₁ is connected to the mixing / adsorption tank 1 via valves V ₁ , V ₂ and line L ₂ .

The cation exchange resin storage tank 4 is connected to the line L ₂ via the line L ₃ , the valve V ₃ , the metering tank 5 and the valve V ₅ so as to introduce the H-type cation exchange resin into the line L ₂ . Further, in order to send the cation exchange resin in the measuring tank 5 to the line L ₂ , a line L ₄ branched from the line L ₁ between the valves V ₁ and V ₂ is connected to the measuring tank 5 through the valve V _4. Yes. Although not shown here, pure water may be used to feed the H-type cation exchange resin from the measuring tank 5.

The lower end of the mixing and adsorption tank 1 is connected to the upper portion of the separation regeneration tank 2 via a line L ₅ and valve V _6. The bottom of the separation regeneration tank 2 is strainer 8 is installed, the line L ₈ on the lower side of the strainer _8, Shimizu via valve V _8, V ₁₀ and line L ₆ is capable introduced.

Further, to introduce a regenerant to the line L _8, the regenerant reservoir 6 is connected to the line L ₈ through the valve V ₉ and line L _9.

A line L ₇ having valves V ₇ and V ₁₄ is branched from the line L ₆ to send out separation waste liquid, and the end of the line L ₇ is connected to the resist component processing apparatus 3.

In order to return the H-type cation exchange resin regenerated in the separation / regeneration tank 2 to the cation exchange resin storage tank 4, a line L ₁₃ having a valve V ₁₃ is arranged between the separation / regeneration tank 2 and the cation exchange resin storage tank 4. It is installed.

The top of the separation regeneration tank 2 is connected to a line _{L 7} via a line _{L 10} and valve _{V 12.} A water-soluble organic solvent extraction line L ₁₁ having a valve V ₁₁ branches from a line L ₁₀ on the separation and regeneration tank 2 side of the valve V ₁₂ .

Water-soluble organic solvent containing water to be introduced into the mixing and adsorption tank 1 (liquid to be treated), open the valve V _1, V _2, introduced from the line L _1, L ₂ a predetermined amount of the liquid to be treated to the tank 1 To do. To introduce the H-shaped cation exchange resin in vessel 1 by opening the valve V _3, it is metered by introducing H-shaped cation exchange resin measuring tank 5 from the resin storage tank 4 through line L _3. Next, the valves V ₄ and V ₅ are opened, the liquid to be treated is supplied from the line L ₄ , the weighed resin is sent out to the line L ₂ and introduced into the mixing / adsorption tank 1.

  Thereafter, the liquid to be treated is mixed with the H-type cation exchange resin by the stirrer 7 in the mixing / adsorption tank 1, and exchanged and adsorbed in a suspended state.

When the pH of the liquid is stabilized at 6 to 7 after stirring for a predetermined time (for example, 10 to 60 minutes), the valve V ₆ is opened and the mixed liquid is introduced into the separation and regeneration tank 2 from the line L ₅ . In the separation / regeneration tank 2, the liquid and the water-soluble organic solvent adsorption cation exchange resin are separated by filtering with the strainer 8. The separated liquid is sent to the resist component processing apparatus 3 from the lines L ₆ and L ₇ .

  As the resin component treatment apparatus 3, a concentrator, a hydrothermal reaction apparatus, or the like is used, and water-soluble resin component treatment such as concentration and hydrothermal reaction is performed on the separated liquid. Since the separation liquid is dealkalized by contact with the H-type cation exchange resin, insolubilization of the water-soluble resin component in the processing apparatus 3 is prevented, and even when heating and concentration are performed, salts and water-soluble resin components Thus, water-soluble resin component treatment such as concentration and hydrothermal reaction can be performed efficiently without precipitation.

After all the liquid in the separation / regeneration tank 2 is sent to the resist component processing apparatus 3 through the strainer 8 and the lines L ₆ and L ₇ , the valves V ₆ and V ₇ are closed and the valves V ₈ , V ₁₀ and V ₁₂ are closed. Is opened, water is sent to the separation / regeneration tank 2, and the cation exchange resin is washed with water. Washing waste water is fed from the line L ₁₀ to the resist component processor unit 3.

Then, the valve V ₁₂ is closed, the valve V _9, V ₁₁ is opened, introducing diluted regenerant (e.g. hydrochloric acid) in water line L ₈ from the regenerant tank 6 to the separator reproducing apparatus 2, cation exchange resin The water-soluble organic solvent is eluted from This elution treatment regenerates the cation exchange resin. Elution wastewater (in this case, MEA-containing water) is taken out via lines L ₁₀ and L ₁₁ and sent to an anion exchange resin tower (not shown) to remove the acid component derived from the regenerant.

After elution is completed, the valve V ₉ is closed, by introducing water only from the line L ₈ to the separation regeneration tank 2, to rinse the H-shaped cation exchange resin 9 with water. The rinse waste water is discharged out of the system through lines L ₁₀ and L ₁₁ .

Thereafter, the valves V ₁₁ and V ₁₄ are closed, and the valves V ₇ , V ₁₂ and V ₁₃ are opened. As a result, water is introduced into the separation and regeneration tank 2 via the lines L ₈ , L ₇ and L _10, and the H-type cation exchange resin 9 in the tank 2 is returned to the cation exchange resin storage tank 4 via the line L _13. Is done.

  In this way, the water-soluble organic solvent having an amino group is recovered as an aqueous solution from the water-soluble organic solvent-containing water. In the water-soluble organic solvent recovery apparatus of FIG. 1, the H-type cation exchange resin is stirred and mixed with the water-soluble organic solvent-containing water in the mixing / adsorption tank 1, so that it passes through a fixed bed water-flow cation exchange resin tower. Clogging as in the case of water does not occur, and operation can be performed stably over a long period of time.

It is a flowchart of the water-soluble organic solvent containing water collection | recovery apparatus which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mixing / adsorption tank 2 Separation / regeneration tank 3 Resist component processing apparatus 4 Cation exchange resin storage tank 5 Measuring tank 6 Regenerant storage tank

Claims (12)

A method for recovering water-soluble organic solvent from water-containing organic solvent-containing water having an amino group,
Bringing the water-containing organic solvent-containing water into contact with an H-form cation exchange resin, causing the water-soluble organic solvent to be exchanged and adsorbed onto the cation exchange resin;
A method for recovering a water-soluble organic solvent having an amino group, wherein the water-soluble organic solvent is eluted from the cation exchange resin and recovered.   The method for recovering a water-soluble organic solvent having an amino group according to claim 1, wherein water-soluble organic solvent-containing water and H-type cation exchange resin are mixed and the water-soluble organic solvent is exchange-adsorbed onto the cation exchange resin. . The water-soluble organic solvent-containing water according to claim 2, wherein the water-containing organic solvent-containing water is waste water from a photolithography process, and contains monoethanolamine and a photoresist residue.
After mixing the water-containing organic solvent-containing water and the H-type cation exchange resin, the H-type cation exchange resin adsorbed with the water-soluble organic solvent is separated from the mixed solution, and the water-soluble organic substance is separated from the separated H-type cation exchange resin. A method for recovering a water-soluble organic solvent having an amino group, wherein the solvent is eluted.   The recovery of the water-soluble organic solvent having an amino group according to claim 3, wherein the H-type cation exchange resin is mixed with water-containing organic solvent-containing water so that the pH of the liquid mixture is 6-7. Method.   The method for recovering a water-soluble organic solvent having an amino group according to any one of claims 1 to 4, wherein the water-soluble organic solvent is eluted from the cation exchange resin with an acid.   6. The method for recovering a water-soluble organic solvent having an amino group according to claim 5, wherein the water-soluble organic solvent eluted from the cation exchange resin is brought into contact with the anion exchange resin to remove the anion by ion exchange.   5. The method for recovering a water-soluble organic solvent having an amino group according to claim 1, wherein the water-soluble organic solvent is eluted from the cation exchange resin with an alkali.   The method for recovering a water-soluble organic solvent having an amino group according to any one of claims 1 to 4, wherein the water-soluble organic solvent is eluted from the cation exchange resin with the organic solvent.   The method for recovering a water-soluble organic solvent having an amino group according to any one of claims 1 to 8, wherein the water-soluble organic solvent is eluted after the cation exchange resin having adsorbed the water-soluble organic solvent is washed with water. . An apparatus for recovering a water-soluble organic solvent having an amino group from water-containing organic solvent-containing water having an amino group,
Mixing means for mixing the water-soluble organic solvent-containing water and the H-form cation exchange resin;
Separation means for separating the water-soluble organic solvent-adsorbing cation exchange resin from the mixed solution of the mixing means;
An apparatus for recovering a water-soluble organic solvent having an amino group, comprising: an elution means for bringing the separated water-soluble organic solvent adsorbing cation exchange resin into contact with an eluent to elute the water-soluble organic solvent. The water-washing means for washing the water-soluble organic solvent-adsorbing cation exchange resin separated by the separation means according to claim 10,
An apparatus for recovering a water-soluble organic solvent having an amino group, wherein the water-soluble organic solvent is eluted by the elution means from the water-soluble organic solvent-adsorbing cation exchange resin washed with the water washing means. In Claim 10 or 11, anion exchange means for removing anions from the liquid eluted by the elution means;
An apparatus for recovering a water-soluble organic solvent having an amino group, comprising a concentration means for concentrating the liquid from the anion exchange means.

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