KR102054944B1 - Electrodeionization with excellent boron removal efficiency - Google Patents

Abstract

The present invention relates to an electric deionization device having excellent boron removal efficiency, and more particularly, an EDI having excellent boron removal efficiency by producing ultrapure water by mixing boron selective ion exchange resin in an appropriate ratio with an ion exchange resin present in the EDI. Relates to modules and systems.

Description

Electrodeionization with excellent boron removal efficiency

The present invention relates to a module and a system of an electrodeionization (EDI) for high-efficiency boron removal, and more particularly, to an EDI module and system in which boron removal efficiency is remarkably improved by using a boron selective ion exchange resin. will be.

EDI stands for Electrodeionization and is called an electrodeionization device. EDI is a water treatment technology that can separate dissolved ions from water when electricity is applied using an ion exchange membrane and an ion exchange resin. No chemical treatment for cleaning is required and is generally used for polishing after Reverse Osmosis.

The EDI system is a new technology that compensates for the shortcomings of the ion exchange resin tower facility. The electrodialysis dilution chamber is filled with conductive materials such as ion exchange resins to reduce wastewater generation and improve resistance and current efficiency in electrodialysis. It is a process that can be reduced.

The EDI module is composed of a dilution chamber, a concentration chamber, and an electrode chamber by alternately arranging a cation exchange membrane and an anion exchange membrane between an anode and a cathode. Generally, a dilution chamber is filled with a cation exchange resin and an anion exchange resin. When DC power is applied to the anode and cathode of the module, ions in the dilution chamber move through the ion exchange membrane to the concentration chamber by the applied DC power, and the ion concentration in the dilution chamber is gradually lost, thereby producing ultrapure water. .

The ion exchange resin used in the EDI module is a cation exchange resin and an anion exchange resin. Generally, the cation exchange resin is a strong acid cation exchange resin (SO3-H type), and the anion exchange resin is a strong base anion exchange resin ( NH 3 + OH Type) is used. The ion exchange resin used in the EDI does not require regeneration unlike other ion exchange resin processes, because when DC power is applied to the EDI, the water between the ion exchange membrane-ion exchange resin and the ion exchange resin-ion exchange resin This is because the H + ions and OH- ions are decomposed, and through this water decomposition reaction, the ion exchange resin is regenerated into H Type and OH Type.

In the semiconductor industry, boron dissolved in water can weaken PN bonds or lower the production yield. Therefore, the demand for the production of ultrapure water without boron is increasing in semiconductor grade ultrapure water production. Boron content of up to 50 parts per trillion (ppt) is required.

As a method for removing boron in conventional semiconductor grade ultrapure water production, for example, Japanese Patent Laid-Open No. 2004-261643 discloses a method of using a structure that allows the concentration chamber to pass in the reverse direction of the desalination chamber. Japanese Patent Publication No. 2003-210946 describes a method of using a structure in which the thickness of the inlet and the outlet of the desalination chamber is adjusted differently, and Korean Patent Publication No. 2008-0113767 further includes a reverse osmosis membrane device and a water softener. A method of using the structure is described.

Currently, a separate polishing process is used at the rear end of EDI to remove boron in ultra pure water, but the concentration of boron in ultrapure water is controlled at the end of EDI. Continuous production is not possible and additional labor costs are required for the regeneration and addition of ion exchange resins.

Therefore, the present inventors studied for efficient removal method of boron in the production of semiconductor-grade ultrapure water, and when the boron-selective ion-exchange resin is mixed with the ion exchange resin existing in the EDI at an appropriate ratio, the ultra-pure water is produced. It shows the effect of boron reduction through the use of boron-selective ion exchange resin, which uses regenerated OH type, which can be regenerated without additional chemical treatment through EDI, so it is suitable for use as a resin filled in EDI. By this, the present invention was completed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an EDI module and a system having excellent boron removal efficiency in which boron-selective ion exchange resins are mixed with an ion exchange resin present in an electrodeionization (EDI) to improve boron removal efficiency in ultrapure water. .

In order to achieve the above object, the present invention is the positive electrode, the negative electrode, the positive and negative ion exchange membrane is arranged alternately between the dilution chamber (Dilute Chamber), Concentrate Chamber (Concentrate Chamber), and Electrolyte Chamber (Electrolyte Chamber) It consists of, the dilution chamber is filled with an anion exchange resin, cation exchange resin and boron selective ion exchange resin, it provides an EDI (Electrodeionization) module for boron removal or reduction.

In addition, the present invention is the positive electrode, the negative electrode, the positive and negative ion exchange membrane is arranged alternately between the positive electrode and the negative electrode in an EDI module consisting of a dilution chamber, a concentration chamber, and an electrolyte chamber, an anion exchange resin, Provided is a method for removing or reducing boron in ultrapure water using an EDI module, including mixing and filling a cation exchange resin and a boron selective ion exchange resin.

In addition, the present invention is a pure water generating module for generating pure water by filtering the raw water supplied from the outside; An EDI module filled with a boron-selective ion exchange resin mixed with an ion exchange resin present in the EDI according to the present invention for purifying pure water generated in the pure water generating module; A storage tank module for storing ultrapure water from which ions are removed from the EDI module; And a dispenser module for discharging the ultrapure water generated by the ultrapure water generation module to the outside.

EDI module and system according to the present invention by reducing the boron concentration in the ultra-pure water to about 1/4 to 1/3 level, while maintaining the specific resistance of the ultra-pure water compared to the conventional EDI using only ion exchange resin, boron removal efficiency It can improve about 4 to 3 times.

In addition, the present invention establishes optimum conditions for the mixing ratio and the installation position of the boron selective ion exchange resin in mixing the boron selective ion exchange resin with the ion exchange resin present in the EDI, thereby producing ultrapure water using EDI. The boron removal efficiency can be maximized.

1 is a plan view of an EDI internal cell according to the present invention.
2 is a photograph of an EDI according to the present invention.
3 is a plan view of an EDI cell according to Embodiment 1 of the present invention:
① mixed ion exchange resin: strong acid cation exchange resin, strong basic ion exchange resin; And
② Boron selective ion exchange resin.
4 is a plan view of an EDI cell according to Embodiment 2 of the present invention:
① mixed ion exchange resin: strong acid cation exchange resin, strong basic ion exchange resin; And
② Boron selective ion exchange resin.

Hereinafter, the present invention will be described in detail.

The present invention

A positive electrode, a negative electrode, and a cation and an anion exchange membrane are alternately arranged between the positive electrode and the negative electrode to constitute a dilute chamber, a concentration chamber, and an electrolytic chamber.

An anion exchange resin, a cation exchange resin and a boron selective ion exchange resin are mixed and filled in the dilution chamber,

Electrodeionization (EDI) module for boron removal or abatement is provided.

The anion exchange resin and the cation exchange resin are preferably mixed at a volume ratio of 7: 3 to 5: 5, and more preferably at a volume ratio of 7: 3.

The boron-selective ion exchange resin is preferably 1 to 10% (v / v) of the total mixed ion exchange resin, more preferably 3 to 10% (v / v).

The EDI module is preferably a top-down module composed of a deionized bed at the top and a polishing bed at the bottom of the EDI.

The mixed ion exchange resin mixed with the anion exchange resin, the cation exchange resin and the boron-selective ion exchange resin is filled in only one of the upper and lower portions of the EDI, and the mixed ion exchange of the anion exchange resin and the cation exchange resin in the remaining upper or lower portion thereof. The resin is preferably filled, and more preferably, the mixed ion exchange resin mixed with the boron selective ion exchange resin is filled in the lower part of the EDI.

The present invention is directed towards according to the principles of the when boron is removed from the inside EDI, typically boron is present in the form of H ₃ BO ₃ in water, and hardly ttiji ionic, the water H ₃ BO ₃ is encountered with OH B It is ionized to (OH) ^4- , and this time, it uses the principle of being transferred to the concentration chamber through the ion exchange resin and the ion exchange membrane inside the EDI.

EDI can be divided into two main areas: one is a deionized bed where ions are removed and one is a polishing bed. In the deionized bed, the ions contained in the water are removed. In the polishing bed, since there are almost no ions, water decomposition occurs between the ion exchange membrane-ion exchange resin and the ion exchange resin-ion exchange resin, and the resin is regenerated. In this polishing bed, OH ^- ion generated by water decomposition meets H ₃ BO ₃ , which is boron in water, and is ionized to B (OH) ^4- to allow boron treatment through EDI.

In addition, the present invention is an EDI module comprising a dilution chamber, a concentration chamber, and an electrolyte chamber by alternately arranging a cation and an anion exchange membrane between the anode, the cathode, the anode and the cathode,

And mixing and filling an anion exchange resin, a cation exchange resin and a boron selective ion exchange resin in the dilution chamber of the EDI module.

The present invention provides a method for removing or reducing boron in ultrapure water using an EDI module.

In the above method, the anion exchange resin and the cation exchange resin are preferably mixed at a volume ratio of 7: 3 to 5: 5, and more preferably at a volume ratio of 7: 3.

In the above method, the boron-selective ion exchange resin is preferably 1 to 10% (v / v) of the total mixed ion exchange resin, and more preferably 3 to 10% (v / v).

In the method, the EDI module is preferably a top-down module composed of a deionized bed at the top and a polishing bed at the bottom of the EDI.

In the above method, the mixed ion exchange resin mixed with the anion exchange resin, the cation exchange resin and the boron-selective ion exchange resin is filled in only one of the upper part or the lower part of the EDI, and the anion exchange resin and the cation exchange in the remaining upper part or the lower part. Preferably, the mixed ion exchange resin of the resin is filled, and the mixed ion exchange resin mixed with the boron selective ion exchange resin is more preferably filled in the lower part of the EDI.

In addition, the present invention is a pure water generating module for generating pure water by filtering the raw water supplied from the outside;

An EDI module filled with a boron-selective ion exchange resin mixed with an ion exchange resin present in the EDI according to the present invention for purifying pure water generated in the pure water generating module;

A storage tank module for storing ultrapure water from which ions are removed from the EDI module; And,

It provides a EDI system for removing or reducing boron, including; a dispenser module for discharging the ultrapure water generated by the ultrapure water generation module to the outside.

In the EDI system, the pure water generating module may include a filter for filtering the raw water to remove particles, and / or a reverse osmosis filter for generating pure water by pressurizing and filtering impurities of the filtered raw water filtered by the filter. Can be.

The reverse osmosis filter may be connected to a discharge passage for discharging pure water, if necessary, and a drain valve may be installed on the discharge passage.

In the EDI system, the EDI module may be arranged by stacking a plurality of cells.

The EDI system may further include an ultrapure water filtering module positioned between the storage tank module and the dispenser module to filter the ultrapure water supplied from the storage tank module.

In the EDI system, the operation is as follows. First, the raw water introduced into the pure water generating module is filtered while passing through a reverse osmosis filter, thereby generating pure water. Pure water generated in the pure water generating module is introduced into the EDI module. When direct current is applied to the EDI module 200, ions of pure water introduced into the EDI module 200 may be moved from the dilution chamber to the concentration chamber, thereby producing pure water from which the ions are removed from the dilution chamber. The concentrated water concentrated in the concentration chamber can be drained to the outside or reused as raw water flowing into the reverse osmosis filter. The ultrapure water generated in the EDI module is stored in the storage tank module. The ultrapure water stored in the storage tank module is supplied to an additional filtering module or to the dispenser module.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

< Example  1>

In the EDI dilution chamber, the volume ratio of ion exchange resin is set to anion exchange resin: cation exchange resin 7: 3, and CRB03 from Mitsubishi Chemical, a boron selective ion exchange resin, is added 1, 3, 5, 10 and 20% of the total volume ratio. After the three ion exchange resins were evenly mixed, the resistivity and boron concentration of ultrapure water produced through EDI were measured. The EDI module used was a top-down module.

The anion exchange resin used in the experiment was a strong basic anion exchange resin, a cation exchange resin was used a strong acid cation exchange resin, two types of resins were used Samyang, Dow chemical ion exchange resin.

The used EDI module was designed and used directly, and the structure of the EDI module is shown in FIG. 3.

The specific resistance measurement was measured using the Ultrameter II 4P product of Myron L Company, Ultrameter II 4P product was used to express the water resistance value by measuring the value of the current flowing through the voltage of the water.

The boron concentration was measured using Agilent Technologies' 7700x ICP-MS, and the method of measuring ICP-MS is an electronic plasma state by flowing a mixture of an inert gas such as argon and a spray sample along the axis of the co-frequency coil. Was produced, and the light emission thereby was used as a light source.

Resistivity (M.Ωcm) Boron Concentration (ppb) Tap water 0.0020 to 0.0040 155 Ro treatment water 0.01 to 0.20 130 EDI Processed Water CRB03-00 15.5 51.6 CRB03-01 15.5 44.2 CRB03-03 15.4 15.4 CRB03-05 15.1 12.1 CRB03-10 14.3 12.4 CRB03-20 8.6 33.8

As a result of the experiment, the ratio of boron-selective ion exchange resin occupied 1 to 5%, and the resistivity was almost similar, whereas the concentration of boron was gradually decreased, and when the ratio of boron-selective ion exchange resin was 10%, resistivity Drops and boron concentration also increased slightly (Table 1).

In particular, when 20% of the boron-selective ion exchange resin is used, the excess of the ion exchange resin is injected compared to the space of the dilution chamber, resulting in a decrease in the pressure of the EDI stack and a decrease in the resistivity of the flow rate and the ultrapure water. There was a tendency to increase. This is caused by a decrease in the flow rate of the dilution chamber due to the excessive injection of ion exchange resin and thus the flow of the flow path is not smooth (Table 1).

< Example  2>

In the EDI dilution chamber, the volume ratio of ion exchange resin is set to anion exchange resin: cation exchange resin 7: 3, and the two ion exchange resins are evenly mixed, and the capacity of the mixed ion exchange resin is equally divided into two parts. CRB03 from Mitsubishi Chemical, an exchange resin, was evenly mixed with the ion exchange resin divided by dividing 5% of the total volume ratio. The resin containing the boron-selective ion exchange resin was placed in either the upper or lower portion of the EDI dilution chamber, and the mixed ion exchange resin of the anion exchange resin and the cation exchange resin was placed at the upper or lower portion of the EDI dilution chamber. Then, the specific resistance and boron concentration of ultrapure water produced through EDI were measured. The EDI module used was a top-down module.

The anion exchange resin used in the experiment was a strong basic anion exchange resin, a cation exchange resin was used a strong acid cation exchange resin, two types of resins were used Samyang, Dow chemical ion exchange resin.

The used EDI module was designed and used directly, and the structure of the EDI module is shown in FIG. 3.

The specific resistance measurement and the measurement of boron concentration were measured in the same manner as in Example 1.

Resistivity (M.Ωcm) Boron Concentration (ppb) Tap water 0.0020 to 0.0040 155 Ro treatment water 0.01 to 0.20 130 EDI Processed Water CRB03-00 15.5 51.6 CRB03-Top 15.6 43.1 CRB03-Lower 15.3 12.0

Since the EDI module used in the above is a top-down module, the upper part of the EDI consists of a deionized bed and the lower part of the polishing bed. As a result of the experiment, the boron-selective resin is installed in the polishing bed inside the EDI to significantly reduce the boron concentration. It was confirmed that it is (Table 2).

Claims (10)

The EDI module is composed of a dilution chamber, a concentration chamber, and an electrolyte chamber by alternately arranging a cation and an anion exchange membrane between the anode and the cathode, the anode and the cathode.
An anion exchange resin, a cation exchange resin and a boron selective ion exchange resin are mixed and filled in the dilution chamber.
here,
The anion exchange resin and cation exchange resin are mixed in a volume ratio of 7: 3,
The boron selective ion exchange resin is 3 to 10% (v / v) of the total mixed ion exchange resin,
The EDI module is a top-down module consisting of a deionized bed at the top of the EDI and a polishing bed at the bottom of the EDI module.
The mixed ion exchange resin mixed with anion exchange resin, cation exchange resin and boron selective ion exchange resin is filled only in the polishing bed, which is the lower part of the EDI, and in the upper deionized bed, Characterized in that the mixed ion exchange resin of the cation exchange resin is filled,
Electrodeionization module for boron removal or abatement.
delete delete delete delete A method of removing or reducing boron in ultrapure water using an electrodeionization (EDI) module for removing or reducing boron according to claim 1.
delete delete Pure water generating module for generating pure water by filtering the raw water supplied from the outside;
Electrical De-ionization (EDI) module for boron removal or reduction of claim 1 for purifying the pure water generated in the pure water generation module;
A storage tank module for storing ultrapure water from which ions are removed from the EDI module; And
It includes; a dispenser module for discharging the ultrapure water generated by the pure water generation module to the outside
EDI system for boron removal or abatement.
The method of claim 9,
Located between the storage tank module and the dispenser module, EDI system for boron removal or reduction further comprising an ultrapure water filtering module for filtering the ultrapure water supplied from the storage tank module.

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