JP2005066411A - Method and apparatus for treating hydrochloric acid-containing waste liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for treating hydrochloric acid-containing waste liquid which can remove charged components from the hydrochloric acid-containing waste liquid to obtain treated water by a simple structure, and recover hydrogen chloride from the hydrochloric acid-containing waste liquid. <P>SOLUTION: In this method, an electric field is applied to the hydrochloric acid-containing waste liquid 1 through a diffusion layer 12 to generate treated water 2 not containing hydrochloric acid, negatively charged components-containing gas-liquid mixed water 3, and positively charged components-containing gas-liquid mixed water 4, chlorine gas 5 is separated from the negatively charged components-containing gas-liquid mixed water and hydrogen gas 6 is separated from the positively charged components-containing gas-liquid mixed water, and the chlorine gas and the hydrogen gas are reacted to generate hydrogen chloride 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for treating a hydrochloric acid-containing waste liquid that recovers hydrogen chloride from a hydrochloric acid-containing waste liquid generated from a semiconductor manufacturing process, a petroleum refining process, a photographic development process, and the like and obtains treated water from which charged components are removed from the hydrochloric acid-containing waste liquid Relates to the device.

  Conventionally, as a method for treating hydrochloric acid-containing waste liquid, there is a method of removing charged components such as ions with an ion exchange resin (see Patent Document 1). In this treatment method, the charged components are randomly adsorbed by positive and negative ion exchange resins, and therefore cannot be recovered as hydrochloric acid or the like. In addition, since the adsorption capacity of ion exchange resins is limited, the ion exchange resin cannot be used when the adsorption capacity is exceeded, and it is necessary to discard all of them or to regenerate them with acid and alkali. Therefore, when hydrochloric acid or other ions are present in a large amount in the waste liquid, a large amount of ion exchange resin waste is generated, and frequent introduction of a new ion exchange resin is required.

Alternatively, as a method for recovering hydrochloric acid or hydrogen chloride from hydrochloric acid-containing waste liquid, there is an electrolysis method using an ion exchange membrane as seen in the salt electrolysis industry (see Patent Document 2). In this method, an ion exchange membrane produced by forming an ion exchange resin into a film is placed between electrodes, and an electric field is applied to obtain chlorine gas from the anode and hydrogen gas from the cathode. In this method, there is a problem in the durability of the ion exchange membrane, and in particular, since an anion exchange membrane is extremely weak, an electrolytic device using a cation exchange membrane is used. However, depending on such an ion exchange membrane electrolysis method, since negatively charged components other than the chlorine component remain in the treated water from which hydrochloric acid or the like has been removed, it is necessary to perform some kind of treatment on these.
JP 2003-144858 A JP 2003-41388 A

  An object of the present invention is to provide a treatment method and apparatus for a hydrochloric acid-containing waste liquid that can obtain treated water from which a charged component has been removed from the hydrochloric acid-containing waste liquid with a simple structure and that can recover hydrogen chloride from the hydrochloric acid-containing waste liquid. .

  The invention of claim 1 is a method for treating hydrochloric acid-containing waste liquid, wherein an electric field is applied to the hydrochloric acid-containing waste liquid through a diffusion layer to contain hydrochloric acid-free treated water, negatively charged component-containing gas-liquid mixed water, and positively charged component-containing Producing gas-liquid mixed water, separating chlorine gas from the negatively charged component-containing gas-liquid mixed water, separating hydrogen gas from the positively-charged component-containing gas-liquid mixed water, and reacting the chlorine gas and the hydrogen gas To produce hydrogen chloride.

  The invention of claim 2 is an apparatus for treating a hydrochloric acid-containing waste liquid, wherein the hydrochloric acid-containing waste liquid is introduced and an electric field is applied to the hydrochloric acid-containing waste liquid through a diffusion layer so that the treated water does not contain hydrochloric acid and the negatively charged component-containing gas liquid Electrolyzer for generating mixed water and positively charged component-containing gas-liquid mixed water, gas-liquid separator for separating chlorine gas from negatively charged component-containing gas-liquid mixed water, and hydrogen from positively-charged component-containing gas-liquid mixed water A gas-liquid separator that separates gas and a hydrogen chloride generation tower that reacts the chlorine gas and the hydrogen gas to generate hydrogen chloride are provided.

  According to a third aspect of the present invention, the electrolysis apparatus is provided in contact with the treatment water chamber through the diffusion layer, the treatment water chamber in which the hydrochloric acid-containing waste liquid is introduced to generate the treatment water, and the diffusion layer An electrode is provided on the opposite side, and a gas-liquid mixed water chamber for generating the negatively charged component-containing gas-liquid mixed water or the positively-charged component-containing gas-liquid mixed water is provided.

According to a fourth aspect of the present invention, the electrode is a bipolar electrode in which platinum is coated on one surface of a titanium plate.
In the invention of claim 5, a plurality of diffusion layers having different pore sizes are provided in series, and a plurality of treatment water chambers for generating treatment water containing charged component impurities having different compositions are formed between the diffusion layers. The configuration is as follows.

The invention of claim 6 is configured such that the treated water chamber is filled with a filler.
In the invention of claim 7, the diffusion layer is made of a metal material such as stainless steel or titanium, or a ceramic material, or a polymer material such as polyimide, cellulose or polysulfone, or an organic material such as polypropylene or polyethylene. Alternatively, the structure is made of a halogen-based organic material such as vinyl chloride or fluorocarbon.

In the invention of claim 8, the material of the electrolytic cell that accommodates the treated water chamber and the gas-liquid mixed water chamber is a metal material such as stainless steel or titanium, or an organic material such as polypropylene, polyethylene, or acrylic, or chlorinated. The structure is a halogen-based organic material such as vinyl or fluorocarbon.
According to a ninth aspect of the present invention, an inner surface of an electrolytic cell that accommodates the treated water chamber and the gas-liquid mixed water chamber is provided with a lining such as vinyl chloride, silicon, or fluorocarbon.

  ADVANTAGE OF THE INVENTION According to this invention, the processing method and apparatus of the hydrochloric acid containing waste liquid which can collect | recover hydrogen chloride from a hydrochloric acid containing waste liquid while obtaining the treated water which removed the charged component from the hydrochloric acid containing waste liquid by simple structure can be provided. .

  Below, the Example of the processing method and apparatus of the hydrochloric acid containing waste liquid which concern on this invention is described.

As shown in FIG. 1, the hydrochloric acid-containing waste liquid treatment apparatus of this embodiment includes an electrolyzer 16, gas-liquid separators 17 and 18, and a hydrogen chloride generator 14 as main components.
The electrolyzer 16 has one surface of a titanium plate coated with platinum, the platinum-coated surface serving as an anode, and the titanium surface acting as a cathode, and the number provided between the bipolar electrodes 13. A fluororesin diffusion layer 12 having a micron pore size, and a fluororesin provided between the bipolar electrode 13 and the diffusion layer 12 and between the diffusion layers 12 and having a liquid inlet 23 and outlets 24 and 25. The spacers 11 are arranged as one unit, and the units are arranged in series with several tens to several hundreds as a guide.

  With such a configuration, the hydrochloric acid-containing waste liquid 1 generated in the semiconductor manufacturing process or the like is introduced from the inlet 23 of the spacer 11 between the diffusion layers 12, and an electric field is generated from the electrodes 9 and 10 disposed at both extremes of the electrolysis apparatus 16. The positively charged components such as hydrogen ions and the negatively charged components such as chloride ions contained in the hydrochloric acid-containing waste liquid 1 are passed through the holes of several microns in the diffusion layer 12 in the direction of the negative electrode 10 and the positive electrode 9, respectively. To the gas-liquid mixed water chambers 21 and 22 between the electrode and the diffusion layer.

  At the same time, chloride ions in the gas-liquid mixed water chamber 21 between the anode 9 and the diffusion layer 12 become chlorine gas by an oxidation reaction promoted by platinum on the anode surface, and this is gas-liquid mixing chamber 21 between the anode 9 and the diffusion layer. From the outlet 24 as the negatively charged component-containing gas-liquid mixed water 3 together with the liquid. At the other cathode 10, water is converted into hydrogen gas by a reduction reaction and flows out from the outlet 25 in the same manner as the positively charged component-containing gas-liquid mixed water 4, and the gas-liquid separators 17, downstream of the outlets 24, 25, The chlorine gas 5 and the hydrogen gas 6 are separated from the liquid by 18.

  The chlorine gas 5 and the hydrogen gas 6 separated by the gas-liquid separators 17 and 18 are introduced into the hydrogen chloride production tower 14 from separate inlets 26 and 27, respectively. The hydrogen chloride generation tower 14 is maintained at several tens of degrees Celsius by the cooling water 15, and the introduced chlorine gas 5 and hydrogen gas 6 are brought into contact with each other to release hydrogen and become hydrogen chloride. The closed cycle can be completed by reusing this in the semiconductor manufacturing process or the like.

  Further, when hydrochloric acid is produced, hydrogen chloride produced in the hydrogen chloride production tower 14 may be introduced into a hydrochloric acid production tower maintained at several tens of degrees Celsius by cooling water, and contacted and dissolved in water to be used as hydrochloric acid. it can.

  In this embodiment, the electrolyzer 16 has platinum or a positive electrode 9 coated with platinum and a negative electrode 10 as a pair at both ends thereof, and a diffusion layer 12 is disposed from the center toward the electrodes 9 and 10, respectively. While the hydrochloric acid-containing waste liquid 1 passes through the chamber between the diffusion layers 12, the positive electrode 9 and the diffusion layer 12 are discharged from the outlet 28 as treated water 2 from which an electric field is applied from the electrodes 9 and 10 to remove charged components. The negatively charged component-containing gas / liquid mixed water 3 is discharged from the outlet 24 from the chamber between, and the positive charged component-containing gas / liquid mixed water 4 is discharged from the outlet 25 from the chamber between the negative electrode 10 and the diffusion layer 12. . The hydrogen chloride generation tower 14 then introduces the chlorine gas 5 separated from the negatively charged component-containing gas-liquid mixed water 3 obtained from the electrolyzer 16 and the hydrogen gas 6 separated from the positively-charged component-containing gas-liquid mixed water 4. The reaction is carried out under cooling conditions.

  By applying an electric field from the electrodes 9 and 10 to the hydrochloric acid-containing waste liquid 1 in the chamber between the diffusion layers 12, positively charged components such as hydrogen ions and negatively charged components such as chlorine components contained in the hydrochloric acid-containing waste liquid 1 are generated. Electrophoresis and movement in the direction of the positive electrode 9 and the negative electrode 10 through the diffusion layer 12 respectively remove the positively charged component and the negatively charged component from the hydrochloric acid-containing waste liquid 1. On the other hand, the chlorine component that has moved into the chamber between the positive electrode 9 and the diffusion layer 12 together with the negatively charged component becomes chlorine gas due to the oxidation reaction at the anode, and conversely, water becomes hydrogen gas due to the reduction reaction at the cathode.

  The chlorine gas 5 and the hydrogen gas 6 separated by these are introduced into a hydrogen chloride production tower 14 in a cooled state, and the chlorine gas 5 and the hydrogen gas 6 are rapidly subjected to a combustion reaction to remove the heat of reaction, thereby removing the hydrogen chloride gas 19 Is generated. As a result, hydrogen chloride 19 is recovered from the hydrochloric acid-containing waste liquid 1, and the hydrochloric acid-containing waste liquid 1 can be treated water 2 from which positive and negative charged components have been removed.

  In this example, the electrode in the middle part of the electrolysis apparatus 16 is a bipolar electrode 13, and one unit of electrodes 9 and 10 at both ends and the diffusion layer 12 therebetween is installed in a plurality of stages in series, and a hydrochloric acid-containing waste liquid 1 is passed between the diffusion layers 12 of each unit, and an electric field is applied from the positive electrode 9 and the negative electrode 10 at both extremes thereof, so that the processing capacity per electrolyzer is large, and compared with a single unit electrolyzer. Power consumption can be suppressed.

  The hydrochloric acid-containing waste liquid 1 is intended for waste liquids containing acids other than hydrochloric acid such as semiconductor processes, waste liquids containing organic solvents such as petroleum refining processes, or waste liquids containing harmful charged components such as photographic development processes. For example, in the waste liquid generated in the semiconductor process, the charged component can be separated simultaneously with hydrochloric acid. In addition, the waste liquid generated in the petroleum refining process contains an organic solvent, so that it is possible to treat even an ion exchange resin or ion exchange membrane that cannot be used. Alternatively, harmful positive and negative charged components such as those contained in photographic developing waste liquid can be simultaneously separated.

  If the material of the diffusion layer 12 is a metal material such as stainless steel or titanium, it is excellent in heat resistance, strength resistance, chemical resistance, etc., and secondary elution from the material can be suppressed. Moreover, if it is a ceramic material, it is excellent in heat resistance, strength resistance, and chemical resistance similarly to a metal material, and can suppress secondary elution from a material. Alternatively, if a polymer material such as polyimide, cellulose, or polysulfone is used, a minute pore size at the atomic level can be provided. Alternatively, an organic material such as polypropylene or polyethylene can be made inexpensive. On the other hand, if a halogen-based organic material such as vinyl chloride or fluorocarbon is used, it can be easily processed with excellent heat resistance and chemical resistance.

  If the electrolytic cell is made of a metal material such as stainless steel or titanium, it is excellent in heat resistance, strength resistance, chemical resistance, etc., and secondary elution from the material can be suppressed. Alternatively, if an organic material such as polypropylene, polyethylene, or acrylic is used, it can be inexpensive and easy to process. On the other hand, if a halogen-based organic material such as vinyl chloride or fluorocarbon is used, it can be easily processed with excellent heat resistance and chemical resistance. Alternatively, if the inner surface of the electrolytic cell is lined with vinyl chloride, silicon, or fluorocarbon, durability can be improved at a low cost.

  If the treated water chamber 20 sandwiched between the diffusion layers 12 is filled with a filler, among the impurities contained in the hydrochloric acid-containing waste liquid 1, components that interact with the filler can be selectively separated.

  In a single unit of the electrolysis apparatus 16, a plurality of diffusion layers 12 having different hole diameters are arranged between the positive and negative electrodes 9, 10, and 13, and treated treated water flows out from the respective chambers between the diffusion layers 12. With this configuration, the negatively chargeable impurities and the positively chargeable impurities can be separated for each particle diameter according to the hole diameter of the diffusion layer 12.

The figure which shows the processing method and apparatus of the hydrochloric acid containing waste liquid of the Example of this invention.

Explanation of symbols

1 ... hydrochloric acid-containing waste liquid, 2 ... treated water, 3 ... negatively charged component-containing gas / liquid mixed water, 4 ... positively charged component-containing gas / liquid mixed water, 5 ... chlorine gas, 8 ... positively charged component-containing water, 7 ... negatively charged Component-containing water, 6 ... hydrogen gas, 9 ... positive electrode, 10 ... negative electrode, 11 ... spacer, 12 ... diffusion layer, 13 ... bipolar electrode, 14 ... hydrogen chloride generator tower, 15 ... cooling water, 16 ... electrolyzer , 17, 18 ... Gas-liquid separator, 19 ... Hydrogen chloride gas, 20 ... Treated water chamber, 21, 22 ... Gas-liquid mixed water chamber, 23 ... Inlet, 24, 25, 28 ... Outlet, 26, 27 ... Introduction port.

Claims (9)

  An electric field is applied to the waste liquid containing hydrochloric acid through the diffusion layer to produce treated water that does not contain hydrochloric acid, gas-liquid mixed water containing negatively charged components, and gas-liquid mixed water containing positively charged components. Treatment of hydrochloric acid-containing waste liquid, wherein chlorine gas is separated from water, hydrogen gas is separated from the gas-liquid mixed water containing the positively charged component, and hydrogen chloride is produced by reacting the chlorine gas with the hydrogen gas. Method.   An electrolysis apparatus in which a hydrochloric acid-containing waste liquid is introduced and an electric field is applied to the hydrochloric acid-containing waste liquid via a diffusion layer to generate hydrochloric acid-free treated water, a negatively charged component-containing gas-liquid mixed water, and a positively-charged component-containing gas-liquid mixed water A gas-liquid separator that separates chlorine gas from the negatively charged component-containing gas-liquid mixed water, a gas-liquid separator that separates hydrogen gas from the positively-charged component-containing gas-liquid mixed water, the chlorine gas, and the hydrogen An apparatus for treating a hydrochloric acid-containing waste liquid, comprising: a hydrogen chloride production tower that reacts gas to produce hydrogen chloride.   The electrolysis apparatus includes a treatment water chamber in which the hydrochloric acid-containing waste liquid is introduced to generate the treatment water, and an electrode on the opposite side of the diffusion layer provided in contact with the treatment water chamber via the diffusion layer. The apparatus for treating waste liquid containing hydrochloric acid according to claim 2, further comprising a gas-liquid mixed water chamber for generating the negatively charged component-containing gas-liquid mixed water or the positively-charged component-containing gas-liquid mixed water.   4. The apparatus for treating a waste liquid containing hydrochloric acid according to claim 3, wherein the electrode is a bipolar electrode in which one surface of a titanium plate is coated with platinum.   A plurality of diffusion layers having different pore diameters are provided in series, and a plurality of treated water chambers for generating treated water containing charged component impurities having different compositions are formed between the diffusion layers. The apparatus for treating a hydrochloric acid-containing waste liquid according to claim 3.   The apparatus for treating a waste liquid containing hydrochloric acid according to claim 3, wherein the treatment water chamber is filled with a filler.   The diffusion layer may be a metal material such as stainless steel or titanium, or a ceramic material, or a polymer material such as polyimide, cellulose or polysulfone, or an organic material such as polypropylene or polyethylene, or vinyl chloride or fluorocarbon. 4. The apparatus for treating a hydrochloric acid-containing waste liquid according to claim 3, comprising a halogen-based organic material.   The material of the electrolytic cell that accommodates the treated water chamber and the gas-liquid mixed water chamber is a metal material such as stainless steel or titanium, or an organic material such as polypropylene, polyethylene, or acrylic, or a halogen such as vinyl chloride or fluorocarbon. 4. The apparatus for treating a hydrochloric acid-containing waste liquid according to claim 3, wherein the apparatus is an organic material. 4. The apparatus for treating hydrochloric acid-containing waste liquid according to claim 3, wherein the inner surface of the electrolytic cell that accommodates the treated water chamber and the gas-liquid mixed water chamber is provided with a lining such as vinyl chloride, silicon, or fluorocarbon. .

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