WO2014006742A1 - Dispositif de traitement d'eaux usées salines et procédé de traitement de celles-ci - Google Patents

Dispositif de traitement d'eaux usées salines et procédé de traitement de celles-ci Download PDF

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WO2014006742A1
WO2014006742A1 PCT/JP2012/067319 JP2012067319W WO2014006742A1 WO 2014006742 A1 WO2014006742 A1 WO 2014006742A1 JP 2012067319 W JP2012067319 W JP 2012067319W WO 2014006742 A1 WO2014006742 A1 WO 2014006742A1
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concentration
salt
electrode chamber
negative electrode
sodium
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PCT/JP2012/067319
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English (en)
Japanese (ja)
Inventor
亜由美 幡野
山本　浩貴
佐々木　洋
松尾　俊明
沖代　賢次
重雄 幡宮
みさき 隅倉
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株式会社日立製作所
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Priority to PCT/JP2012/067319 priority Critical patent/WO2014006742A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D7/00—Carbonates of sodium, potassium or alkali metals in general
    • C01D7/07—Preparation from the hydroxides
    • 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
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D1/00—Oxides or hydroxides of sodium, potassium or alkali metals in general
    • C01D1/04—Hydroxides
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/02—Treatment of water, waste water, or sewage by heating
    • C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F2001/5218—Crystallization
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/08—Seawater, e.g. for desalination
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/10—Nature of the water, waste water, sewage or sludge to be treated from quarries or from mining activities
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
    • C02F2103/36—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
    • C02F2103/365—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds from petrochemical industry (e.g. refineries)
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/46115—Electrolytic cell with membranes or diaphragms
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00—Apparatus for treatment of water, waste water or sewage
    • C02F2201/46—Apparatus for electrochemical processes
    • C02F2201/461—Electrolysis apparatus
    • C02F2201/46105—Details relating to the electrolytic devices
    • C02F2201/4612—Controlling or monitoring
    • C02F2201/46145—Fluid flow

Definitions

  • the present invention relates to a salt effluent treatment apparatus and a treatment method thereof, and more particularly to a salt effluent treatment apparatus suitable for volume reduction treatment of wastewater containing sodium chloride and a treatment method thereof.
  • accompanying water containing salt is generated along with oil and natural gas.
  • This accompanying water is usually returned to the wells of oil and gas fields in order to suppress land subsidence.
  • the generated amount is limited by the treatment of the accompanying water. There may be a need to approach zero.
  • seawater desalination there is a case where the concentrated salt water is returned to the sea to cause fluctuations in the environment, and it is desirable to reduce the wastewater containing salt as much as possible.
  • Patent Document 1 adopts a method in which electricity, steam, and the like necessary for concentration of wastewater are covered by supply of power by an internal combustion engine such as a gas turbine and a generator, and supply of steam by a steam generator by heat of combustion exhaust gas. ing. This method has problems associated with improvement in energy use efficiency and reduction in the generation amount of exhaust gas such as carbon dioxide. Further, Patent Document 1 describes a method of further reducing the volume to a salt solid centered on NaCl by evaporating and drying the salt drainage.
  • An example of conventional methods for converting water containing sodium chloride into other valuable materials is the production of caustic soda and liquefied chlorine by electrolysis.
  • This method is to manufacture using the electrochemical reaction shown in the following formula.
  • the sodium chloride concentration is preferably lower from the viewpoint of current utilization efficiency, but is preferably higher from the viewpoint of facility scale. Considering these balances, when the sodium chloride concentration is adjusted to about 15% by weight, it is possible to reduce the equipment scale while maintaining the current utilization efficiency at a high level.
  • chlorine ions are oxidized at the positive electrode and volatilized as chlorine gas, and the remaining sodium ions move to the negative electrode side.
  • hydrogen gas generated by reduction of hydrogen ions volatilizes, and the remaining hydroxide ions generate sodium hydroxide (caustic soda) together with sodium ions.
  • chlorine gas For chlorine gas, it is usually due to condensation of impurities centered on moisture by cooling to 0 to 15 ° C (rough purification), drying by aeration to concentrated sulfuric acid, compression and cooling to below the boiling point of chlorine (-34 ° C). Through the liquefaction process, it is converted to liquefied chlorine. Liquefied chlorine is used as a raw material for synthesizing hydrochloric acid, vinyl chloride, hypochlorite and the like.
  • chlorine gas is corrosive and harmful, it is necessary to select equipment for handling the gas before drying, selection of piping materials (glass lining material, Teflon (registered trademark) seal, etc.), detection of gas leaks, and the like.
  • piping materials glass lining material, Teflon (registered trademark) seal, etc.
  • detection of gas leaks and the like.
  • hydrogen gas is a flammable gas, it is necessary to ensure sufficient exhaust and safety so that it does not remain in the electrolytic cell.
  • the present invention has been made in view of the above points, and the object of the present invention is not only low cost, but also high yield and high efficiency in a substance that can effectively use sodium chloride with low environmental load.
  • An object of the present invention is to provide a salt effluent treatment apparatus and a treatment method thereof that can be converted.
  • the salt wastewater treatment apparatus of the present invention is formed of a concentration device for concentrating salt wastewater containing sodium chloride, a positive electrode chamber, a negative electrode chamber, and an ion exchange membrane separating the positive electrode chamber, and the concentration device
  • An electrolyzer that electrolyzes the salt drainage concentrated in 1), a generator that generates electrical energy necessary for concentrating the salt drainage in the concentration device and electrolyzing the salt drainage in the electrolytic layer;
  • the ammeter was measured with the ammeter, referring to the salt concentration of the positive electrode chamber and the negative electrode chamber measured with the salt concentration meter and the current value between the electrodes measured with the ammeter and a previously acquired database.
  • a maximum value of the amount of change in the sodium hydrogen carbonate concentration value relative to the current value is obtained, and is provided with an arithmetic unit that controls the flow rate of the high-concentration salt water in the positive electrode chamber so as to be the maximum value
  • the positive electrode chamber includes a salt drainage supply unit and a discharge unit and a chlorine gas discharge unit
  • the negative electrode chamber includes a solution supply unit to the negative electrode, a discharge unit for hydrogen and other gases, and a carbon dioxide gas blowing unit.
  • thermometer In addition to the sodium salt recovery unit, a thermometer, a salt concentration meter, and a water level meter are installed in the positive electrode chamber and the negative electrode chamber, and an ammeter and a voltmeter are installed to measure the current and voltage between the electrodes.
  • the maximum value of the amount of change in the sodium bicarbonate concentration value with respect to the high concentration in the positive electrode chamber by the positive electrode that controls the current between the electrodes and the flow rate of the salt drain to the electrolytic cell so as to be the maximum value. Control the flow rate of salt water Characterized in that it comprises a that computing device.
  • drain of this invention WHEREIN: The 1st process which concentrates the salt waste water containing sodium chloride, and produces
  • a sixth step of recovering a gas containing chlorine generated from the gas and a gas containing hydrogen generated from the negative electrode A sixth step of recovering a gas containing chlorine generated from the gas and a gas containing hydrogen generated from the negative electrode; a seventh step of measuring the temperature of the high-concentration salt drainage generated in the first step; An eighth step of measuring the temperature of the exhaust gas generated in the course of the second step, a ninth step of measuring the temperature and salt concentration of the solution installed in the electrolytic cell, the voltage applied to the electrode, and A tenth step of measuring current; an eleventh step of introducing the temperature, salt concentration, and current value into the computing device; and a salt concentration curve for these measured values and the current value previously held in the computing device.
  • FIG. 1 is a system configuration diagram showing Embodiment 1 of a salt drainage treatment apparatus of the present invention. It is a system block diagram which shows Example 2 of the processing apparatus of the salt waste_water
  • FIG. 7 is a plan view of FIG. 6.
  • salt drainage containing sodium chloride discharged from the concentrator is electrolyzed in an electrolytic cell to obtain sodium hydroxide, which is then burned.
  • Exhaust gas is aerated, carbon dioxide contained in combustion exhaust gas is absorbed, and reacted with caustic soda to generate sodium hydrogen carbonate (sodium bicarbonate, NaHCO 3 ) and / or sodium carbonate (Na 2 CO 3 ) to produce carbon dioxide.
  • the invention of the salt effluent treatment apparatus and the treatment method for fixing the slag and recovering the slag is achieved.
  • FIG. 14 shows an example in which the salt drainage treatment apparatus is applied to an actual coal gas field.
  • the salt effluent treatment system shown in the figure includes an RO membrane system for treating salt effluent associated with a coal gas field, a system for obtaining clean water by a MED (Multi-Effect-Distillation) system, and power / heat supply for driving the system.
  • a system an electrolysis / volume reduction system for obtaining valuable salts such as sodium carbonate and sodium hydrogen carbonate by treating high-concentration salt effluent generated in the MED system, and a chlorine refining / liquefaction system for treating chlorine gas produced by electrolysis Composed.
  • 101 is a gas field
  • 102 is a gas treatment device
  • 103 is a water absorption pump
  • 104 is a strainer
  • 105 is a pretreatment device such as an MF membrane or UF membrane
  • 106 is a pressurized air tank
  • 107 is an alkali supply tank
  • 108 is an acid supply tank
  • 109 is a neutralization tank
  • 110 is a high-pressure water pump
  • 111 is an RO membrane desalination device
  • 112 is a chemical cleaning / drainage treatment device
  • 113 is a pressure energy recovery device
  • 114 is a backwashing device (blower).
  • 115 is a product gas supply blower
  • 116 is an MED device
  • 117 is a heat exchanger
  • 118 is a heat dissipation unit
  • 119 and 120 are ejectors
  • 121 is a gas turbine
  • 122 and 148 are generators
  • 123 is an exhaust heat recovery boiler
  • 124 , 125, 126, 131, 132, 140, 141, 142, 145, 152 are liquid feed pumps
  • 127 is a transformer
  • 128 is an electrolytic cell.
  • 129 is a scrubber
  • 130 and 134 are powder separators
  • 133 is a CO 2 absorber
  • 135 is a sodium carbonate tank
  • 136 is a heat exchange type cooler
  • 137 is a gas-liquid separator
  • 138 is a dryer
  • 139 is a thicker
  • a sulfuric acid tank 143 is a sulfuric acid concentration tank
  • 144 is a chlorine gas liquefying device
  • 146 is a liquefied chlorine tank
  • 147 is a steam turbine.
  • Sodium hydroxide obtained by electrolysis is aerated with combustion exhaust gas to absorb carbon dioxide contained in the combustion exhaust gas and react with caustic soda to react with sodium bicarbonate (sodium bicarbonate, NaHCO 3 ) and / or sodium carbonate (Na 2 When carbon dioxide is fixed by generating CO 3 ) and recovered, the dissolved and absorbed amount of carbon dioxide is increased by converting it to an aqueous solution of caustic soda compared to an aqueous solution of sodium chloride.
  • aeration method there are a method in which aeration is directly performed on the electrolytic cell, a method in which the alkaline solution discharged from the electrolytic cell is aerated, a method in which the alkaline solution discharged from the electrolytic cell is sprayed on combustion exhaust gas, and the like.
  • the temperature of the reaction solution increases due to electrolysis or heat of combustion exhaust gas, so that the solubility of NaHCO 3 or Na 2 CO 3 increases and is recovered as a solution. There is a merit that can be done.
  • the temperature is preferably about 50 to 70 ° C. in order to reduce the evaporation of moisture from the reaction solution from the viewpoint of reducing the mass of chlorine gas.
  • a method for aeration of the alkaline solution discharged from the electrolytic cell for example, there is a method of using an ejector to draw and dissolve the exhaust gas by the negative pressure accompanying the flow rate of the solution and the narrowing of the flow path.
  • the production ratio of sodium bicarbonate and sodium carbonate depends on the concentration of carbon dioxide in the gas, and when the carbon dioxide concentration is 5% or more, the production of sodium bicarbonate becomes dominant.
  • the final product can be recovered as a solid using the heat of the exhaust gas.
  • the heat of the exhaust gas not only free water but also water of crystallization of NaHCO 3 and Na 2 CO 3 can be devolatilized.
  • the production ratio of sodium bicarbonate and sodium carbonate depends on the concentration of carbon dioxide in the gas.
  • the carbon dioxide concentration is 5% or more, the production of sodium bicarbonate becomes dominant.
  • crystal water is removed.
  • the combustion exhaust gas is separated in advance before the solution is sprayed. It is desirable to receive spraying with a small amount of alkaline solution.
  • sodium hydroxide is generated by electrolysis of salt waste water, and this sodium chloride and carbon dioxide are reacted to increase the efficiency of generating sodium hydrogen carbonate (sodium bicarbonate) and / or sodium carbonate.
  • sodium hydrogen carbonate sodium bicarbonate
  • sodium carbonate sodium bicarbonate
  • Embodiment 1 of the salt drainage treatment apparatus of the present invention will be described.
  • FIG. 1 shows a first embodiment of the salt drainage treatment apparatus of the present invention.
  • the salt effluent treatment apparatus of the present embodiment includes an electrolysis mechanism such as an electrolyzer 14, a MED (evaporation concentration apparatus) 2, a power generation mechanism including a generator 24, and a control mechanism including an arithmetic unit 1. ing.
  • high-concentration salt water 29 from the salt drain 41 and the electrolytic cell 14 is supplied to the MED (evaporation and concentration device) 2 by the pump 7 or the like, where it is concentrated and purified, and the water 30 Separated into concentrated salt water 28.
  • the separated clean water 30 can also be supplied to the negative electrode side.
  • the separated high-concentration salt drainage 28 is supplied to the electrolytic cell 14.
  • the electric power for operating the MED (evaporation concentrator) 2 is electric energy 23 supplied from the generator 24 driven by the gas turbine 12.
  • the number of the gas turbines 12 and the generators 24 may be increased to two or more as necessary when the power is insufficient. Moreover, by providing a plurality of gas turbines in this way, it can be used as a backup in case of failure.
  • the high-concentration salt drainage 28 supplied from the MED (evaporation concentration apparatus) 2 to the electrolytic cell 14 is in the positive electrode chamber of the electrolytic cell 14, and the aqueous sodium carbonate solution 34 heated by the heat exchanger 13 is the electrolytic cell.
  • the negative electrode chambers 14 are respectively supplied.
  • a water level meter (+) 3 and a water level meter (-) 4 for measuring the water level, a salt concentration meter (+) 5 and a salt concentration meter (-) 6 for measuring the salt concentration are installed in the positive electrode chamber and the negative electrode chamber, respectively.
  • the measured values measured by the water level meter (+) 3, the water level meter ( ⁇ ) 4, the salt concentration meter (+) 5, and the salt concentration meter ( ⁇ ) 6 are input to the arithmetic unit 1. . Also, an ammeter 51 for measuring the current of the positive electrode and the negative electrode in the positive electrode chamber and the negative electrode chamber, and a voltmeter 52 for measuring the voltage are installed, and the current and voltage measured by the ammeter 51 and the voltmeter 52 are calculated by an arithmetic unit. 1 is applied to control the amount of power applied for electrolysis.
  • the high-concentration salt drainage 28 in the positive electrode chamber and the sodium carbonate aqueous solution 34 in the negative electrode chamber are electrolyzed by the current flowing from the electrodes inserted in the positive electrode chamber and the negative electrode chamber, respectively. It is converted into an aqueous sodium oxide solution 26.
  • the chlorine gas 18 generated in the positive electrode chamber during the electrolysis in the electrolytic cell 14 is supplied to the cooler 8, cooled by the cooler 8, and then separated and washed into water vapor and salts by the mist separator 9. The Then, after drying with the drying tower 10 to which the concentrated sulfuric acid 19 is supplied, it is cooled and pressurized by the cooler 11 and stored as liquid chlorine 21 in the tank. The generated hydrogen is supplied to the gas turbine 12 as fuel.
  • the high-concentration salt water 29 discharged from the positive electrode chamber of the electrolytic cell 14 is supplied again to the MED (evaporation concentration device) 2 and concentrated.
  • Reference numeral 20 denotes a route of waste sulfuric acid from the drying tower 10.
  • the sodium hydroxide aqueous solution 26 discharged from the negative electrode chamber of the electrolytic cell 14 is supplied to a carbonation tank 32 as a reaction tank by a pump 7 and sprayed in the carbonation tank 32 to be converted into fine droplets. And the surface area is increased.
  • the carbon dioxide tank 32 in such a state is supplied with the exhaust gas 25 containing carbon dioxide from the gas turbine 12 through the heat exchanger 13 by the blower 33, and the sodium hydroxide aqueous solution 26 and the exhaust gas 25 containing carbon dioxide are brought into contact with each other.
  • the sodium hydroxide aqueous solution 26 reacts with the carbon dioxide in the exhaust gas 25 to become a sodium hydrogen carbonate aqueous solution, which is separated into a mixed aqueous solution of sodium carbonate and sodium hydrogen carbonate in the centrifugal separation mechanism 17 which is a recovery device, Stored as sodium bicarbonate 27.
  • sodium hydroxide aqueous solution 26 By bringing the sodium hydroxide aqueous solution 26 into contact with the exhaust gas 25 containing carbon dioxide, it can be converted into sodium bicarbonate 27 and / or sodium carbonate with high efficiency.
  • the aqueous sodium hydrogen carbonate solution produced is heated at 150-200 ° C. to cause dehydration and decarboxylation, and is converted into sodium carbonate solid.
  • the gas turbine 12 is supplied with hydrogen gas 22 as a fuel from the positive electrode chamber of the electrolytic cell 14, and the gas turbine 12 drives the generator 24 to generate power.
  • the electric energy 23 generated by the generator 24 is used for the operation of the MED (evaporation concentration apparatus) 2 and the electrolytic cell 14.
  • the positive electrode chamber and the negative electrode measured by the salt concentration meter (+) 5 and the salt concentration meter ( ⁇ ) 6 installed in the positive electrode chamber and the negative electrode chamber of the electrolytic cell 14 will be described in detail later.
  • the current value between the electrodes measured by the ammeter 51 that measures the salt concentration of the chamber and the current between the positive electrode and the negative electrode is input to the arithmetic device 1, and the current stored in the arithmetic device 1 is referred to
  • the maximum value of the change amount of the sodium hydrogen carbonate concentration value with respect to the current value measured by the total 51 is obtained, and the flow rate of the high-concentration salt water in the positive electrode chamber is controlled by the arithmetic device 1 so as to be the maximum value. .
  • sodium hydroxide is generated by electrolysis of the salt effluent, and by reacting this sodium chloride with carbon dioxide, sodium hydrogen carbonate (sodium bicarbonate) and / or sodium carbonate is produced.
  • the efficiency of generation can be increased.
  • the cost is low, but also the effect of converting the sodium chloride into a substance that can be effectively used with a low environmental load can be obtained with high yield and high efficiency.
  • salt wastewater treatment it becomes possible to preferentially produce a more valuable salt, and to minimize the salt concentration in the salt wastewater.
  • the temperature of the wastewater can be lowered, reducing the impact on the environment. it can.
  • FIG. 2 shows a second embodiment of the salt drainage treatment apparatus of the present invention.
  • a sodium hydroxide aqueous solution 26 discharged from the negative electrode chamber of the electrolytic tank 14 is supplied and has a CO 2 blowing section 16.
  • a cooling precipitation tank 15 which is a reaction tank is provided.
  • Other configurations are the same as those of the first embodiment.
  • the sodium hydroxide aqueous solution 26 supplied from the electrolytic cell 14 reacts with carbon dioxide in the exhaust gas 25 supplied to the cooling precipitation vessel 15 and introduced from the CO 2 blowing section 16, It becomes sodium hydrogencarbonate aqueous solution, and when this is cooled by the cooling precipitation tank 15, it precipitates as a sodium hydrogencarbonate crystal
  • the sodium hydrogen carbonate crystals are separated into a mixed aqueous solution of sodium carbonate and sodium hydrogen carbonate by a centrifugal separation mechanism 17 which is a recovery device, and stored as sodium hydrogen carbonate 27 in a tank.
  • the sodium hydrogen carbonate aqueous solution is led to the heat exchanger 13, where it is heated and supplied again to the negative electrode chamber of the electrolytic cell 14, but no solution is supplied from the positive electrode chamber to the negative electrode chamber. .
  • Such a configuration of the present embodiment can provide the same effects as those of the first embodiment.
  • FIG. 3 shows a third embodiment of the salt drainage treatment apparatus of the present invention.
  • the positive electrode side can be made into sodium carbonate and sodium hydrogen carbonate, and can be put into the negative electrode side.
  • a chlorine ion concentration meter (+) 31 that measures the chlorine ion concentration in the positive electrode chamber of the electrolytic cell 14 is provided, and the measured chlorine ion concentration data in the positive electrode chamber is input to the arithmetic unit 1. It has become. Further, when chlorine ions remain on the positive electrode side, hypochlorous acid is generated when this is introduced to the negative electrode side, and therefore it is necessary to perform electrolysis so that chlorine ions do not exist as much as possible.
  • FIG. 4 shows a fourth embodiment of the salt drainage treatment apparatus of the present invention.
  • the CO 2 blowing part 16 of the exhaust gas 25 is connected to the negative electrode side of the electrolytic cell 14, the exhaust gas 25 is directly introduced into the electrolytic cell 14, and sodium hydroxide produced by electrolysis is converted into hydrogen carbonate. This is converted to sodium or sodium carbonate. That is, the electrolytic cell 14 is a reaction vessel.
  • Other configurations are the same as those of the second embodiment.
  • Such a configuration of the present embodiment has the same effect as that of the second embodiment, but also has an effect of eliminating the need for a mechanism for contacting exhaust gas with the wastewater after electrolysis.
  • FIG. 5 shows a fifth embodiment of the salt drainage treatment apparatus of the present invention.
  • FIG. 6 and FIG. 7 show an example of an electrolytic cell employed in each embodiment of the present invention.
  • 200 is an electrolytic cell constituting an electrolytic cell
  • 201 is a positive electrode chamber
  • 202 is a negative electrode chamber
  • 203 is high-concentration salt water filled in the positive electrode chamber 201
  • 204 is negative electrode electrolyzed water filled in the negative electrode chamber 202
  • 205 is a positive electrode
  • 206 is a negative electrode
  • 207 is a temperature sensor of the positive electrode chamber 201
  • 207 ' is a temperature sensor of the negative electrode chamber 202
  • 208 is a salt concentration sensor of the positive electrode chamber 201
  • 208' is a salt concentration sensor of the negative electrode chamber 202
  • 209 is Chlorine gas
  • 210 is a chlorine gas recovery port
  • 211 is a hydrogen gas discharge port
  • 212 is a negative electrode electrolyzed water inlet
  • 213 is a high-concentration salt water inlet
  • 214 is hydrogen gas
  • the positive electrode chamber 201 and the negative electrode chamber 202 are installed adjacent to each other only through the ion exchange membrane 221, and the positive electrode 205 and the negative electrode 206 are adjacent to the ion exchange membrane 221 in the positive electrode chamber 201 and the negative electrode chamber 202, respectively. In addition, it is laid in parallel with the ion exchange membrane 221.
  • the positive electrode 205 and the negative electrode 206 are provided with a positive electrode terminal 219 and a negative electrode terminal 220, respectively.
  • the positive electrode 205 and the negative electrode 206 are preferably made of a plate made of copper, platinum, gold, iridium oxide, or the like, and these may have a mesh shape installed on a current collector. Further, the positive electrode 205 and the negative electrode 206 are preferably arranged as close to the ion exchange membrane 221 as possible in order to minimize loss due to resistance during electrolysis.
  • ion exchange membrane 221 a semi-permeable membrane that selectively permeates cations such as sodium is used. This membrane allows sodium ions to move from the positive electrode to the negative electrode, but chloride ions and hydroxide ions cannot pass through this membrane, so chlorine is accumulated in the positive electrode chamber and sodium hydroxide is accumulated in the negative electrode chamber. The If this ion exchange membrane 221 is not provided, it is not preferable because chloride ions, hydroxide ions, and sodium ions generated at the positive electrode react to generate sodium hypochlorite and the like.
  • the positive electrode chamber 201 is provided with an introduction port 213 and a discharge port 216 for introducing the high-concentration salt water 203, and the high-concentration salt water 203 is input and drained.
  • the negative electrode chamber 202 is provided with an inlet 212 and a discharge port 215 for introducing the negative electrode electrolyzed water 204, and the negative electrode electrolyzed water 204 is input and discharged.
  • the negative electrode electrolyzed water 204 is introduced in order to perform electrolysis with low resistance, and is salt water containing a large amount of sodium ions and the like.
  • the positive electrode chamber 201 is provided with a recovery port 210 for recovering chlorine gas 209 generated by electrolysis
  • the negative electrode chamber 202 is provided with a recovery port 211 for recovering hydrogen gas 214 generated by electrolysis. Yes.
  • the positive electrode chamber 201 and the negative electrode chamber 202 are provided with temperature sensors 207 and 207 ′, salt concentration sensors 208 and 208 ′, and water level meters 217 and 218, respectively.
  • the temperature, salt concentration, and water level measured by these are transferred as data to the arithmetic device 1 shown in the first to fifth embodiments.
  • the electrolytic cell 14 configured in this manner, when an electric field is generated between the positive electrode 205 and the negative electrode 206, a current is generated across the ion exchange membrane 221, and sodium ions flow from the positive electrode 205 side to the negative electrode 206 side.
  • the above-described electrochemical reaction of Chemical Formula 1 and Chemical Formula 2 occurs at the electrode, and chlorine is generated on the positive electrode 205 side and hydrogen is generated on the negative electrode 206 side.
  • sodium hydroxide is formed. It is accumulated in the negative electrode electrolyzed water 204.
  • the electrolytic cell 200 is preferably provided with a small volume with respect to the electrode in order to efficiently electrolyze the high-concentration salt water 203 that has passed therethrough.
  • a plurality of the electrolytic cells 200 are installed in parallel. Thus, it is preferable to perform an electric field.
  • FIG. 8 shows another example of the electrolytic cell employed in each embodiment of the present invention.
  • exhaust gas 25 containing carbon dioxide from the generator 12 is aerated in the negative electrode chamber 202, and sodium hydroxide and carbon dioxide generated in the negative electrode electrolyzed water 204 in the negative electrode chamber 202 are discharged into the negative electrode chamber 202.
  • It is an electrolytic cell for making it react in the inside and obtaining sodium hydrogencarbonate or sodium carbonate.
  • 222 is a carbon dioxide inlet
  • 223 is a carbon dioxide outlet.
  • FIG. 9 shows still another example of the electrolytic cell employed in each embodiment of the present invention.
  • the example shown in the figure shows an electrolytic cell in which a plurality of electrolytic cells 200 shown in FIGS. 6 and 7 are arranged in parallel.
  • 200 is an electrolysis cell
  • 224 is a recovery tube for recovering hydrogen generated in the negative electrode chamber of each electrolysis cell
  • 225 is a recovery tube for recovering chlorine generated in the positive electrode chamber of each electrolysis cell 200
  • 226 is negative electrode electrolysis
  • An introduction pipe for water 204, 227 is an introduction pipe for high-concentration salt drainage to be introduced into the positive electrode chamber, 228 is a discharge pipe for negative electrode electrolyzed water 204, and 229 is an exhaust pipe for high-concentration salt drainage in the positive electrode compartment.
  • FIG. 9 shows an example in which the electrolysis cells 200 shown in FIG. 6 are connected in parallel, but the number of cells in parallel is not particularly limited to this, and a large capacity electrolyzer such as 80 cells to 100 cells is used. It is also possible to form.
  • the hydrogen recovery pipe 224 is a pipe that connects the recovery port 211 provided in the negative electrode chamber of each electrolysis cell 200 in parallel, and is supplied again as fuel for the gas turbine 12, and if necessary. It is exhausted by the power of a blower (not shown).
  • the chlorine recovery pipe 225 is a pipe connecting the chlorine gas recovery port 210 provided in the positive electrode chamber of each electrolysis cell 200 in parallel, and the coolers 8 and 11, the mist separator 9, the drying tower of FIGS. 1 to 5. 10 is introduced into a chlorination section composed of 10 to form liquid chlorine 21 and finally carried out as a valuable resource. If necessary, exhaust is performed by power from a blower (not shown).
  • these liquids are supplied to the electrolysis cell 200 by power of a liquid feed pump or the like separately provided through an introduction pipe 226 of negative electrode electrolyzed water 204 introduced into the negative electrode and an introduction pipe 227 of high-concentration salt drain introduced into the positive electrode.
  • the negative electrode electrolyzed water 204 is fed to a sodium carbonate or sodium hydrogen carbonate recovery unit by the power of a liquid feed pump or the like separately provided through the discharge pipe 228 of the negative electrode electrolyzed water 204
  • the high-concentration salt water 203 is a high concentration of the positive electrode It is introduced into the MED (evaporation concentration apparatus) 2 or the negative electrode chamber 202 through the salt drain discharge pipe 229.
  • FIG. 10 shows still another example of the electrolytic cell employed in each embodiment of the present invention.
  • the example shown in the figure shows an electrolytic cell in which a plurality of electrolytic cells 200 having a mechanism for aeration of carbon dioxide shown in FIG. 8 are arranged in parallel.
  • reference numeral 230 denotes an introduction pipe for the exhaust gas 25 containing carbon dioxide.
  • the introduction pipe 230 is a pipe for connecting the carbon dioxide introduction ports 222 of the electrolysis cells 200 in parallel, and is introduced using power such as a blower (not shown) as necessary.
  • FIG. The horizontal axis is the applied power calculated from the voltage and current values applied to the electrodes inserted in the electrolytic cell 14, and the vertical axis is the amount of sodium hydroxide produced in the negative electrode chamber.
  • the rate at which hydroxide ions are generated by the applied power is equal to or exceeds the rate at which sodium ions pass through the cation permeable membrane. .
  • the rate at which the cation passes through the cation permeable membrane increases as the cation concentration difference increases (for example, Masaharu Saito, Kyoto University of Education Environmental Education Annual Report, No. 2, p. 49-63 (1994)).
  • the predetermined value (WB or WC) is determined by the difference ⁇ [Na + ] in the sodium concentration between the positive electrode chamber and the negative electrode chamber, and ⁇ [Na + ] B ⁇ [Na + ] C.
  • the applied power when the applied power is increased, the rate at which hydroxide ions are generated by the applied power is lower than the rate at which sodium ions pass through the cation permeable membrane. That is, at the applied power WD1 (> WB) at point B1, a loss of applied power occurs.
  • a value of the amount of sodium hydroxide generated with respect to the amount of current applied at each ⁇ [Na + ] is acquired in advance, and this value is stored in the arithmetic unit 1 that is a control mechanism.
  • Each arithmetic device 1 controls the amount of liquid flowing into the positive electrode, the amount of liquid flowing into the negative electrode, the inflow rate of clean water, the gas flow rate, etc. so that the production amount of sodium bicarbonate and sodium carbonate is maximized.
  • the salt concentration in the positive electrode chamber and the negative electrode chamber measured by the salt concentration meter (+) 5 and the salt concentration meter ( ⁇ ) 6 installed in the positive electrode chamber and the negative electrode chamber of the electrolytic cell 14 and the current between the positive electrode and the negative electrode are calculated.
  • the current value between the electrodes measured by the ammeter 51 to be measured is input to the arithmetic device 1, and a sodium hydrogen carbonate with respect to the current value measured by the ammeter 51 is referred to a database stored in the arithmetic device 1 in advance.
  • the maximum value of the change amount of the concentration value is obtained, and the flow rate of the high-concentration salt water in the positive electrode chamber is calculated by the positive electrode that controls the current between the electrodes and the flow rate of the salt drain to the electrolytic cell 14 so as to be the maximum value. 1 is controlled.
  • the amount of sodium hydroxide generated with respect to the applied power can be maximized, and sodium hydroxide can be obtained under the most efficient conditions with no power loss.
  • the speed at which sodium ions pass through the cation permeable membrane is the speed at which sodium ions pass through.
  • a power value that is equal to or greater than is calculated.
  • FIG. 12 is a characteristic diagram for explaining the effect of this example when the temperature of the solution in the electrolytic cell 14 is changed and the difference in sodium ion concentration between the positive and negative electrode chambers is constant.
  • the horizontal axis is the applied power calculated from the voltage and current values applied to the electrodes inserted in the electrolytic cell 14, and the vertical axis is the amount of sodium hydroxide produced in the negative electrode chamber.
  • the ratio of the amount of sodium hydroxide produced to the applied power increases in the order of T1 ⁇ T2 ⁇ T3 in the temperature of the solution in the electrolytic cell 14.
  • the range of T is 40 ° C. or more and 80 ° C. or less.
  • T falls below 40 ° C.
  • the amount of sodium hydrogen carbonate recovered in the cooling precipitation tank 15 decreases.
  • T exceeds 80 ° C. the amount of water evaporated from the electrolytic cell 14 increases, and it becomes difficult to control the temperature of the solution in the electrolytic cell 14.
  • Sodium hydrogen carbonate is obtained by aeration of carbon dioxide to sodium hydroxide produced in the negative electrode chamber by the method shown in FIG. As shown in FIG. 13, the temperature of the high-concentration salt wastewater to be subjected to electrolysis is as high as about 80 ° C., and this is cooled to recover sodium hydrogen carbonate contained above the saturation solubility at that temperature think of.
  • T1 is the temperature at which sodium hydrogen carbonate is recovered
  • T2 is the temperature of the high-concentration salt wastewater during electrolysis.
  • FIG. 15 is a flowchart showing a control method in the salt drainage processing method of this embodiment.
  • the control mechanism in the present embodiment includes (1) Na + concentration difference control mechanism, (2) positive inflow amount control mechanism, (3) negative inflow amount control mechanism, (4) positive outflow amount control mechanism, (5 ) Negative electrode effluent amount control mechanism, (6) Clean water inflow mechanism, and (7) Gas flow rate control mechanism.
  • Each control mechanism captures the following measurements and results: (1) Na + concentration difference control mechanism: electrolytic cell positive electrode chamber Na + concentration meter, electrolytic cell negative electrode chamber Na + concentration meter, (2) Positive electrode influent flow rate control mechanism: MED Na + concentration meter (high concentration salt drainage), MED medium solution thermometer (high concentration salt drainage), electrolytic cell cathode chamber liquid phase thermometer (+), Na + concentration Difference control mechanism, liquid flow meter from MED to positive electrode chamber, (3) Negative electrode inflow liquid amount control mechanism: Na + concentration meter in negative electrode chamber supply water tank, inflow liquid thermometer in negative electrode supply water tank, electrolyzer negative electrode chamber liquid phase thermometer ( ⁇ ), Na + concentration difference control mechanism, Liquid flow meter from negative supply water tank to negative electrode chamber, (4) Positive electrode effluent amount control mechanism: Na + concentration difference control mechanism, liquid flow meter from positive electrode chamber to MED, (5) Negative electrode effluent amount control mechanism: Na + concentration difference control mechanism, liquid flow meter from negative electrode chamber to cooling precipitation tank, (6) Clean water inflow mechanism
  • Each control mechanism adjusts the following flow rate or output from the above measured values and results; (1) Na + concentration difference control mechanism: positive electrode influent amount control mechanism, negative electrode influent amount control mechanism, positive electrode outflow amount control mechanism, negative electrode outflow amount control mechanism, power control mechanism, (2) Positive electrode influent flow rate control mechanism: High-concentration salt drainage liquid flow rate from MED to electrolytic cell positive electrode chamber, (3) Negative electrode inflow liquid amount control mechanism: solution flow rate from the negative electrode supply water tank to the electrolytic cell negative electrode chamber, (4) Positive electrode effluent amount control mechanism: solution flow rate from the electrolytic cell positive electrode chamber to MED, (5) Negative electrode effluent amount control mechanism: solution flow rate from the electrolytic cell negative electrode chamber to the cooling precipitation tank, (6) Clean water inflow mechanism: supply amount of clean water from MED to electrolytic cell negative electrode chamber, (7) Gas flow rate control mechanism: exhaust gas inflow from GT to heat exchanger, (8) Power control mechanism: power applied to the electrolytic cell.
  • 16 and 17 show an example of a specific control flow in the salt drainage treatment method of the present embodiment.
  • the CO 2 concentration in the cooling precipitation tank is 0.01% or more, the reaction between CO 2 and sodium hydroxide proceeds sufficiently, so that the inflow amount of exhaust gas can be further reduced. In this case (when the CO 2 concentration is sufficient), control is performed according to the control flow of FIG.
  • it is less than 0.02% the amount of exhaust gas supplied cannot be reduced because the amount of CO 2 is insufficient. In this case (when the CO 2 concentration is insufficient), control is performed according to FIG.
  • the Na + concentration difference between the positive and negative electrode chambers is less than ⁇ [Na + ] R and the liquid temperature in the electrolytic cell is higher than 80 ° C., the amount of exhaust gas flowing from the gas turbine to the heat exchanger is reduced, By increasing the amount of inflow into the solution in the negative electrode chamber, the Na + concentration difference in the positive and negative electrode chambers is increased.
  • the clean water supplied from MED as a safety device is inject
  • the flow rate of the positive electrode chamber solution is increased, the Na + concentration difference in the positive and negative electrode chambers is increased, and the liquid temperature in the electrolytic cell is further increased.
  • the temperature of the electrolytic cell is in the range of 40 ° C. to 80 ° C., the flow rate of the positive electrode chamber solution is increased or the flow rate of the negative electrode chamber solution is increased to increase the Na + concentration difference between the positive and negative electrode chambers.
  • the flow rates of the positive electrode chamber and the negative electrode chamber solution are as follows: the amount of high-concentration salt drainage flowing from the MED to the positive electrode chamber of the electrolytic cell; the amount of salt water flowing from the positive electrode chamber of the electrolytic cell to the MED; The amount of solution flowing into the negative electrode chamber and the amount of solution flowing from the negative electrode material of the electrolytic cell into the cooling precipitation tank are determined by controlling with a pump. From the concept of FIG. 11 and FIG. 12, the arithmetic unit is calculated from the Na + concentration meter (+) in the positive electrode chamber of the electrolytic cell, the Na + concentration meter ( ⁇ ) in the negative electrode chamber, and the liquid phase temperature in the positive and negative electrode chambers of the electrolytic cell. The optimum applied power is calculated by 1 to determine the applied power amount.
  • the Na + concentration difference between the positive and negative electrode chambers is ⁇ [Na + ] R or more and the liquid temperature in the electrolytic cell is higher than 80 ° C.
  • the exhaust gas inflow from GT to the heat exchanger is reduced, By increasing the amount of inflow into the solution, the Na + concentration difference in the positive and negative electrode chambers is increased.
  • the clean water supplied from MED as a safety device is inject
  • the liquid temperature of the electrolytic cell When the liquid temperature of the electrolytic cell is lower than 40 ° C., the amount of exhaust gas flowing from GT to the heat exchanger is increased, and the amount of solution flowing from the supply water tank in the negative electrode chamber to the negative electrode chamber of the electrolytic cell is increased.
  • the liquid temperature of the electrolytic cell is in the range of 40 ° C. to 80 ° C., the optimum applied power is calculated from the concept of FIG. 11 and FIG. 12 from the liquid phase thermometer in the positive and negative electrode chambers of the electrolytic cell. Determine the amount of power.
  • the CO 2 concentration in the gas turbine exhaust gas fluctuates. For example, when exhaust gas that is deficient with 1% CO 2 flows into an average of 2% CO 2, the concentration of sodium hydrogen carbonate that is generated when the CO 2 concentration decreases is lowered. Therefore, the difference in sodium concentration between the positive electrode chamber and the negative electrode chamber is reduced. At this time, if the CO 2 concentration in the cooling precipitation bath is 0.005%, because it is 0.005% ⁇ 0.01%, the positive and negative electrode chamber Na + concentration of the electrolytic cell in accordance with the flow of FIG. 17, the electrolyte Optimize the bath temperature and applied power.
  • the difference in Na + concentration in the positive and negative electrode chambers is less than ⁇ [Na + ] R and the liquid temperature in the electrolytic cell is higher than 80 ° C.
  • the water supplied from MED is injected to lower the temperature. .
  • the liquid temperature in the electrolytic cell is lower than 40 ° C.
  • the flow rate of the positive electrode chamber solution is increased and the Na + concentration difference in the positive and negative electrode chambers is increased.
  • the temperature of the electrolytic cell is in the range of 40 ° C. to 80 ° C., the flow rate of the positive electrode chamber solution is increased or the flow rate of the negative electrode chamber solution is increased to increase the Na + concentration difference between the positive and negative electrode chambers.
  • the flow rates of the positive electrode chamber and the negative electrode chamber solution are as follows: the high-concentration salt drainage inflow from the MED to the positive electrode chamber of the electrolytic cell; the high-concentration salt drainage outflow from the positive electrode chamber of the electrolytic cell to the MED; The amount of solution inflow from the water tank to the negative electrode chamber of the electrolytic cell and the amount of solution flow from the negative electrode chamber of the electrolytic cell to the cooling precipitation tank are determined by controlling with a pump. From the concept of FIG. 11 and FIG.
  • the arithmetic unit is calculated from the Na + concentration meter (+) in the positive electrode chamber of the electrolytic cell, the Na + concentration meter ( ⁇ ) in the negative electrode chamber, and the liquid phase temperature in the positive and negative electrode chambers of the electrolytic cell.
  • the optimum applied power is calculated by 1 to determine the applied power amount.
  • the optimum applied power is calculated by the arithmetic unit 1 from the liquid phase thermometer in the positive and negative electrode chambers of the electrolytic cell, based on the concept of FIGS. To determine the amount of applied power.
  • FIG. 18 is a specific control flow chart in the salt drainage treatment method of this embodiment that is effective when the sodium chloride concentration in the salt drainage is low.
  • the control mechanism of the present embodiment shown in the figure is as follows: (1) Na + concentration difference control mechanism, (2) polar influent amount control mechanism, (3) negative inflow amount control mechanism, and (4) positive outflow amount control. Mechanism, (5) negative electrode effluent amount control mechanism, (6) clean water inflow mechanism, (7) gas flow rate control mechanism, and (8) positive electrode chamber solution discharge amount control mechanism.
  • Each control mechanism captures the following measurements and results: (1) Na + concentration difference control mechanism: electrolytic cell positive electrode chamber Na + concentration meter, electrolytic cell negative electrode chamber Na + concentration meter, (2) Positive flow rate control mechanism: MED Na + concentration meter (high concentration salt drainage), MED medium solution thermometer (high concentration salt drainage), electrolytic cell positive chamber liquid phase thermometer (+), Na + concentration Difference control mechanism, liquid flow meter from MED to positive electrode chamber, (3) Negative electrode inflow liquid amount control mechanism: Na + concentration meter in negative electrode chamber supply water tank, inflow liquid thermometer in negative electrode supply water tank, electrolyzer negative electrode chamber liquid phase thermometer ( ⁇ ), Na + concentration difference control mechanism, Liquid flow meter from negative supply water tank to negative electrode chamber, (4) Positive electrode effluent amount control mechanism: Na + concentration difference control mechanism, liquid flow meter from positive electrode chamber to MED, (5) Negative electrode effluent amount control mechanism: Na + concentration difference control mechanism, liquid flow meter from negative electrode chamber to cooling precipitation tank, (6) Clean water inflow mechanism: MED liquid temperature
  • Each control mechanism adjusts the following flow rate or output from the above measured values and results; (1) Na + concentration difference control mechanism: positive electrode influent amount control mechanism, negative electrode influent amount control mechanism, positive electrode outflow amount control mechanism, negative electrode outflow amount control mechanism, power control mechanism, (2) Positive electrode influent flow rate control mechanism: High-concentration salt drainage liquid flow rate from MED to electrolytic cell positive electrode chamber, (3) Negative electrode inflow liquid amount control mechanism: solution flow rate from the negative electrode supply water tank to the electrolytic cell negative electrode chamber, (4) Positive electrode effluent amount control mechanism: solution flow rate from the electrolytic cell positive electrode chamber to MED, (5) Negative electrode effluent amount control mechanism: solution flow rate from the electrolytic cell negative electrode chamber to the cooling precipitation tank, (6) Clean water inflow mechanism: supply amount of clean water from MED to electrolytic cell negative electrode chamber, (7) Gas flow rate control mechanism: Exhaust gas inflow from gas turbine to heat exchanger, (8) Power control mechanism: applied power to the electrolytic cell, (9) Positive electrode chamber solution discharge control mechanism: Solution discharge amount from the electro
  • FIG. 19 is a specific control flow chart in the salt drainage treatment method of the present example that is effective when the sodium chloride concentration in the salt drainage is as low as less than 2%.
  • sodium chloride or sodium bicarbonate or sodium carbonate is contained in the salt water, and the salt water is contained.
  • the total concentration [Na + ] a, total of sodium present in the negative electrode of the electrolytic cell as sodium hydrogen carbonate or sodium hydroxide is [Na + ] c, total> [Na + ] a, total Only the production of sodium hydroxide proceeds.
  • the Na + concentration difference between the positive and negative electrode chambers is less than ⁇ [Na + ] R, and the liquid temperature in the electrolytic cell is higher than 80 ° C., the amount of exhaust gas flowing from the gas turbine to the heat exchanger is reduced, and the negative electrode The Na + concentration difference in the positive and negative electrode chambers is increased by increasing the amount of inflow into the chamber solution.
  • the clean water supplied from MED as a safety device is inject
  • the flow rate of the positive electrode chamber solution is increased and the Na + concentration difference in the positive and negative electrode chambers is increased.
  • the temperature of the electrolytic cell is in the range of 40 ° C. to 80 ° C.
  • the flow rate of the positive electrode chamber solution is increased or the flow rate of the negative electrode chamber solution is increased to increase the Na + concentration difference between the positive and negative electrode chambers.
  • the flow rates of the positive electrode chamber and negative electrode chamber solutions are as follows: salt water inflow from the MED to the positive electrode chamber of the electrolytic cell, sodium chloride solution outflow from the positive electrode chamber of the electrolytic cell to the MED, and electrolysis from the supply water tank of the negative electrode chamber.
  • the amount of solution flowing into the negative electrode chamber of the tank and the amount of solution flowing from the negative electrode material of the electrolytic tank into the cooling precipitation tank are determined by controlling with a pump. From the concept of FIGS. 11 and 12, the optimum applied power is determined from the Na + concentration meter (+) in the positive electrode chamber of the electrolytic cell, the Na + concentration meter ( ⁇ ) in the negative electrode chamber, and the liquid phase temperature in the positive and negative electrode chambers of the electrolytic cell. To calculate the applied power amount.
  • the liquid temperature in the electrolytic cell is less than 40 ° C.
  • the amount of exhaust gas flowing from the gas turbine to the heat exchanger is increased, and the amount of solution flowing from the supply water tank in the negative electrode chamber to the negative electrode chamber in the electrolytic cell is increased.
  • the liquid temperature in the electrolytic cell is in the range of 40 ° C. to 80 ° C.
  • the optimum applied power is calculated from the concept of FIGS. 11 and 12 from the liquid phase thermometer in the positive and negative electrode chambers of the electrolytic cell. Determine the amount.
  • the electrolytic cell Optimize the liquid temperature and applied power.
  • the flow rate of the positive electrode chamber solution is increased and the Na + concentration difference in the positive and negative electrode chambers is increased.
  • the temperature of the electrolytic bath is in the range of 40 ° C. to 80 ° C., the flow rate of the positive electrode chamber solution is increased or the flow rate of the negative electrode chamber solution is increased to increase the Na + concentration difference between the positive and negative electrode chambers.
  • the flow rates of the positive electrode chamber and negative electrode chamber solutions are as follows: the amount of sodium chloride aqueous solution flowing from the MED into the positive electrode chamber of the electrolytic cell, the amount of sodium chloride aqueous solution flowing out from the positive electrode chamber of the electrolytic cell to the MED, and the electrolysis from the negative electrode supply water tank. It is determined by controlling the inflow amount of the negative electrode chamber solution in the tank and the inflow amount of the solution from the negative electrode chamber of the electrolytic cell to the cooling deposition tank. From the concept of FIGS.
  • the optimum applied power is determined from the Na + concentration meter (+) in the positive electrode chamber of the electrolytic cell, the Na + concentration meter ( ⁇ ) in the negative electrode chamber, and the liquid phase temperature in the positive and negative electrode chambers of the electrolytic cell. To calculate the applied power amount.
  • Application example 1 An example in which the saltwater treatment apparatus of the present invention is applied when treating the accompanying water discharged from the gas field A in the systems shown in FIGS. 1, 14, 15, 16, and 17 will be described.
  • Cationic species Na 59,000 mg / L, Other cations 700 mg / L or less.
  • Anion species Cl 77, 200 mg / L, CO 3 181 mg / L, HCO 3 23,000 mg / L, Other anions 700 mg / L or less. Moreover, COD is 300 mg / L or less.
  • This salt drainage is put into the positive electrode chamber 201 of the electrolysis cell 200 shown in FIG.
  • the negative electrode chamber 202 is charged with 60,000 mg / L sodium carbonate aqueous solution. This is the electrolyzed water concentration after passing through the centrifugal separation mechanism 17 shown in FIG.
  • the internal methods of the positive electrode side and the negative electrode side of the electrolysis cell 200 are both 1 m ⁇ 1 m ⁇ 0.01 m, and the volume is 10 L.
  • the water temperature at the time of introduction of both is 70 ° C.
  • a voltage of 3V and a current of 60A are applied.
  • bubbles of chlorine gas are generated from the positive electrode, and electrolysis proceeds.
  • sodium ions in the positive electrode chamber 201 move to the negative electrode chamber 202 and the sodium ion concentration in the positive electrode chamber 201 decreases, but the sodium ion concentration adjusting mechanism reduces the sodium ions in the positive electrode chamber 201 and the negative electrode chamber 202. Since the concentration difference is 3% or more, the high-concentration salt drainage is flowed with this state as a steady state, and a stable operation state is obtained.
  • the sodium ion concentration in the negative electrode chamber 202 becomes 72,000 mg / L. This means that 12,000 mg / L sodium ion is increased compared to the initial 60,000 mg / L. This indicates that 21,000 mg / L of sodium hydroxide is generated in the negative electrode chamber 202.
  • This liquid is fed to the carbonation layer 32 shown in FIG. 1 using the pump 7 and sprayed in a spray form. The exhaust gas 25 of the gas turbine 12 is blown into this to perform sodium carbonate conversion of sodium hydroxide, and it is crystallized and collected as a powder (sodium bicarbonate 27) in a tank.
  • the sodium ion concentration in the negative electrode chamber 202 is 72,000 mg / L in this experimental example. This means that 12,000 mg / L sodium ion is increased compared to the initial 60,000 mg / L. This indicates that 21,000 mg / L of sodium hydroxide is generated in the negative electrode chamber 202.
  • the exhaust gas 25 of the gas turbine 12 is blown into the negative electrode chamber 202, and sodium hydroxide is converted to sodium hydrogen carbonate.
  • the sodium hydrogen carbonate generated here is 200,000 mg / L. Since the water temperature is 70 ° C., this concentration of sodium hydrogen carbonate is dissolved in the aqueous solution. This is sent to the cooling precipitation tank 15 and the temperature is lowered to 5 ° C.
  • the slurry which the sodium hydrogencarbonate exceeding 60,000 mg / L which is a saturated dissolution amount recrystallized is obtained.
  • This slurry is sent to the centrifugal separation mechanism 17 and centrifuged at 4000 rpm under a cold temperature of 5 ° C. By this centrifugation, the solution is separated into an aqueous solution containing 60,000 mg / L sodium hydrogencarbonate and sodium hydrogencarbonate crystals having crystal water.
  • the aqueous solution is heated to about 70 ° C. via the heat exchanger 13 and then charged again into the negative electrode chamber 202.
  • Sodium hydrogen carbonate having crystal water is also dried to 200 ° C. or higher by utilizing the exhaust heat of the gas turbine 12. Thereby, anhydrous sodium carbonate crystals are obtained.
  • the sodium carbonate that can be recovered at this time is 4.5 kg when the amount of high-concentration salt drainage flowing through this electrolytic cell is 100 L.
  • FIG. 9 when the decomposition cells 200 are arranged in parallel in 86 cells and processed 8,600 L, 387 kg of sodium carbonate can be recovered.
  • Application Example 3 An application example 3 in which the accompanying water discharged from the gas field B is processed in the systems shown in FIGS. 3, 14, 18, 19, and 20 will be described.
  • Cationic species Na 23,000 mg / L, Other cations 100 mg / L or less.
  • This salt drainage is put into the positive electrode chamber 201 of the electrolysis cell 200 shown in FIG.
  • the negative electrode chamber 202 is charged with 60,000 mg / L sodium carbonate aqueous solution. This is the electrolyzed water concentration after passing through the centrifugal separation mechanism 17 shown in FIG.
  • the internal methods of the positive electrode side and the negative electrode side of the electrolysis cell 200 are both 1 m ⁇ 1 m ⁇ 0.01 m, and the volume is 10 L.
  • the water temperature at the time of introduction of both is 70 ° C.
  • a voltage of 3V and a current of 60A are applied.
  • bubbles of chlorine gas are generated from the positive electrode, and electrolysis proceeds.
  • sodium ions in the positive electrode chamber 201 move to the negative electrode chamber 202, and the sodium ion concentration in the positive electrode chamber 201 decreases.
  • the sodium ion concentration in the positive electrode chamber 201 is almost 0, indicating that the entire amount of sodium chloride contained in the high-concentration salt water that has been charged is electrolyzed.
  • the high-concentration salt water discharged from the positive electrode chamber 201 is an aqueous solution of sodium carbonate and sodium hydroxide, it is caused to flow into the negative electrode chamber of the electrolytic cell 14 as shown in FIG. With this state as a steady state, high-concentration salt drainage is introduced, and a stable operation state is obtained.
  • the sodium ion concentration in the negative electrode chamber 202 is 71,000 mg / L. This means that 11,000 mg / L sodium ion is increased compared to the initial 60,000 mg / L. Thereby, it is shown that 19,000 mg / L of sodium hydroxide is generated in the negative electrode chamber 202.
  • the exhaust gas 25 of the gas turbine 12 is blown into the negative electrode chamber 202, and sodium hydroxide is converted to sodium hydrogen carbonate.
  • the composition of the exhaust gas 25 is the same as that shown in Application Example 1.
  • the sodium carbonate recovered at this time becomes 4.0 kg when the flow rate of the high-concentration salt drainage flowing through the electrolytic cell 14 is 100 L. As shown in FIG. 9, when 86 cells are juxtaposed in parallel as shown in FIG.
  • this invention is not limited to the above-mentioned Example, Various modifications are included.
  • the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.
  • a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
  • Neutralization tank 110 ... High pressure water pump, 111 ... RO membrane desalination device, 112 ... Chemical cleaning / wastewater treatment device, 113 ... Pressure energy recovery device, 114 ... Backwash device, 115 ... Product gas supply blower, 116 ... MED device, 118 ... Heat radiating section, 119, 120 ... Ejector, 123 ... Waste heat recovery boiler, 124, 125, 126, 131, 132, 140, 141, 142, 145, 152 ... Liquid feed pump, 127 ... transformer, 129 ... scrubber, 130, 134 ... powder separator, 133 ... CO 2 absorber, 135 ... sodium carbonate Heater tank 136, heat exchange type cooler, 137 ...
  • Chlorine gas recovery port 211 ... Hydrogen gas recovery port, 212 ... Negative electrode Electrolyzed water inlet, 213 ... High concentration salt water inlet, 214 ... Hydrogen gas, 215 ... Negative electrode electrolyzed water outlet, 216 ... Positive electrode high concentration salt water outlet, 217 ... Water level gauge in positive electrode chamber, 218 ... Negative electrode Room water level gauge, 21 DESCRIPTION OF SYMBOLS 9 ... Positive electrode terminal, 220 ... Negative electrode terminal, 221 ... Ion exchange membrane, 222 ... Introducing port of carbon dioxide, 223 ... Outlet of carbon dioxide, 224 ... Recovery tube for recovering hydrogen generated in negative electrode chamber, 225 ... Positive electrode chamber Recovery pipe for recovering chlorine generated in 226 ...
  • Negative electrode electrolytic water introduction pipe 227 ... High concentration salt drain introduction pipe introduced into the positive electrode chamber, 228 ... Electrolytic water discharge pipe in the negative electrode chamber, 229 ... Positive electrode chamber discharge pipe High-concentration salt drain pipe, 230 ... exhaust gas inlet pipe.

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Abstract

La présente invention concerne un dispositif de traitement d'eaux usées salines grâce auquel du chlorure de sodium peut être converti de manière hautement efficace en une substance efficacement utilisable à haut rendement avec des charges environnementales réduites. Ce dispositif de traitement d'eau usée saline comprend : un concentrateur qui concentre l'eau usée saline ; un réservoir électrolytique dans lequel l'eau usée saline concentrée par le concentrateur est électrolysée ; et un générateur d'énergie électrique qui génère l'énergie électrique qui est nécessaire pour pratiquer l'électrolyse de l'eau usée saline dans la couche de décomposition. Le dispositif comprend : des compteurs de concentration en sel qui ont été disposés respectivement dans la chambre d'électrode positive et la chambre d'électrode négative du réservoir électrolytique ; un ampèremètre qui mesure un courant électrique circulant entre l'électrode positive et l'électrode négative ; et une unité arithmétique qui détermine une valeur maximale du changement de la concentration en hydrogénocarbonate de sodium par rapport à la valeur du courant électrique mesuré par l'ampèremètre, tout en se référant aux concentrations en sel mesurées par les compteurs de concentration en sel, la valeur du courant électrique mesuré par l'ampèremètre, et une base de données pré-acquise, et qui commande le débit d'écoulement de la substance saline à haut concentration dans la chambre d'électrode positive de façon à fournir la valeur maximale.
PCT/JP2012/067319 2012-07-06 2012-07-06 Dispositif de traitement d'eaux usées salines et procédé de traitement de celles-ci WO2014006742A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015194963A1 (fr) * 2014-06-18 2015-12-23 Engsl Minerals Dmcc Procédé pour la production de carbonate de sodium
JP5865495B2 (ja) * 2012-07-06 2016-02-17 株式会社日立製作所 塩排水の処理方法及び装置
CN111670362A (zh) * 2018-01-31 2020-09-15 奥加诺株式会社 过氧化氢浓度的测定系统以及测定方法
US11465925B1 (en) 2022-01-13 2022-10-11 Heimdal Limited Carbon capture method and system

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JPS5123499A (fr) * 1974-05-22 1976-02-25 Rhone Poulenc Ind
JPS5198700A (fr) * 1975-01-22 1976-08-31
JPS5376195A (en) * 1976-12-17 1978-07-06 Diamond Shamrock Corp Electrolysis of diaphragm electrolytic bath employing external adjustment of caustic soda and sodium chrolide concentration
JP2008514406A (ja) * 2004-09-23 2008-05-08 ジョー デイヴィッド ジョーンズ 炭酸塩および／または炭酸水素塩鉱物の同時生成による廃棄物流からの二酸化炭素の除去
JP2008538738A (ja) * 2005-03-08 2008-11-06 ソルヴェイ（ソシエテ アノニム） 塩素誘導体及び炭酸ナトリウムの結晶を共に得るための方法

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JPS5123499A (fr) * 1974-05-22 1976-02-25 Rhone Poulenc Ind
JPS5198700A (fr) * 1975-01-22 1976-08-31
JPS5376195A (en) * 1976-12-17 1978-07-06 Diamond Shamrock Corp Electrolysis of diaphragm electrolytic bath employing external adjustment of caustic soda and sodium chrolide concentration
JP2008514406A (ja) * 2004-09-23 2008-05-08 ジョー デイヴィッド ジョーンズ 炭酸塩および／または炭酸水素塩鉱物の同時生成による廃棄物流からの二酸化炭素の除去
JP2008538738A (ja) * 2005-03-08 2008-11-06 ソルヴェイ（ソシエテ アノニム） 塩素誘導体及び炭酸ナトリウムの結晶を共に得るための方法

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5865495B2 (ja) * 2012-07-06 2016-02-17 株式会社日立製作所 塩排水の処理方法及び装置
JPWO2014006741A1 (ja) * 2012-07-06 2016-06-02 株式会社日立製作所 塩排水の処理方法及び装置
WO2015194963A1 (fr) * 2014-06-18 2015-12-23 Engsl Minerals Dmcc Procédé pour la production de carbonate de sodium
CN111670362A (zh) * 2018-01-31 2020-09-15 奥加诺株式会社 过氧化氢浓度的测定系统以及测定方法
CN111670362B (zh) * 2018-01-31 2022-04-05 奥加诺株式会社 过氧化氢浓度的测定系统以及测定方法
US11465925B1 (en) 2022-01-13 2022-10-11 Heimdal Limited Carbon capture method and system

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