Abstract: Anion exchange membrane and methods of making and using the same. In one embodiment, the anion exchange membrane may be made by a method that includes a two-step polymerization. In the first step, an ?-olefin monomer containing a pendant halide, such as 8-bromo-1-octene, may be polymerized by Ziegler-Natta polymerization to form a first polymer portion, the first polymer portion being a homopolymer. In the second step, the polymerization is charged with a non-functionalized ?-olefin monomer, such as ethylene, thereby forming a second polymer portion, the second polymer being a copolymer made up predominantly of the non-functionalized olefin monomer. If desired, a small amount of an ?-olefin monomer containing a crosslinking functionality may be included in the first and/or second steps. Following the two-step polymerization, the polymer is fabricated into a thin film. Thereafter, the thin film may be functionalized by replacing the pendant halides with pendant cations.

Abstract: A method that forms a metal plating film having a thick film thickness by a solid phase method is provided. The present disclosure is a method that forms the metal plating films of a first metal and a second metal having an ionization tendency larger than an ionization tendency of the first metal. The method includes: depositing the second metal on a surface of a copper base material to form the plating film of the second metal; and depositing the first metal on a surface of the second metal by a solid electroless plating method to form the plating film of the first metal. The solid electroless plating method in the depositing of the first metal is performed using a laminated complex. The laminated complex includes a first substitution-type electroless plating bath, a solid electrolyte membrane, a copper base material, a third metal, a second substitution-type electroless plating bath, and an insulating polymer. The first substitution-type electroless plating bath contains ions of the first metal.

Abstract: The invention relates to a device for drawing off liquid salt, particularly for facilities for purifying wastewater, said device comprising a heating chamber. The heating chamber comprises an inlet for introducing a salt-containing substance and is connected to an outlet for a salt melt. The outlet comprises an outlet channel and an outlet channel end, a cooling region for cooling the salt melt being provided downstream of the outlet channel end. The outlet channel is peripherally surrounded by an outlet wall at least along a section, the outlet comprising a heating element.

Abstract: Devices for electrochemically activating precursor compound through oxidation (or reduction) to produce active compound are provided.

Abstract: The present invention relates to a device and method for controlling the pH of a UpA cell. The device comprises a receiving unit for receiving a preset parameter including a desired pH value; a computing module configured to calculate an UpA cell parameter based on the preset parameter; and a control module configured to control the UpA cell based on the calculated UpA cell parameter.

Abstract: Method for purifying an aqueous composition by removing silicon therefrom, according to which a compound comprising aluminum is added to the aqueous composition in order to obtain a molar aluminum content greater than the molar silicon content in said composition, the pH of the composition is controlled and maintained at a value higher than or equal to 8 and lower than or equal to 10, and the precipitate formed is separated from the aqueous suspension obtained.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein the ion exchange membrane and a cathode chamber inner space in which the gas diffusion electrode is disposed are separated by a liquid retaining member, the outer periphery of the liquid retaining member is held in a void formed in a gasket or a cathode chamber frame constituting the cathode chamber, or the outer periphery and the end face of the outer periphery of the liquid retaining member are sealed, or the outer periphery of the liquid retaining member is joined to and integrated with the gasket.

Abstract: An apparatus and method is provided for the production of alkali metals and caustic solutions. The apparatus and method do not require the use of toxic liquid mercury-sodium amalgam electrodes. The apparatus and methods utilize a bismuth-indium-tin eutectic alloy as a substitute for the mercury electrode used in a conventional Castner-Kellner apparatus.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.

Abstract: Processes and apparatus for purifying brine are provided including (1) providing an aqueous brine solution comprising one or more inorganic salts and one or more organic compounds and (2) conducting at least one unit operation for removing organic compounds from the brine solution to obtain a purified brine solution.

Abstract: There is provided a method of production of chlorine.sodium hydroxide capable of being operated stably and economically by preventing calcium from being deposited in an ion exchange membrane. The liquid retention layer 3 having a liquid retention amount per unit volume of the liquid retention layer of 0.10 g-H2O/cm3 or more and 0.80 g-H2O/cm3 or less is put between the ion exchange membrane 12 and the gas diffusion electrode 16. Calcium ions transferred through the ion exchange membrane 12 easily diffuse, thereby making it possible to suppress increase in an electrolytic voltage and drop in current efficiency generated by deposition of the calcium ions inside the ion exchange membrane 12.

Abstract: A method for electrolytically generating a biocide having an electron deficient carrier fluid and chlorine dioxide, including providing a carrier fluid; providing a pair of electrodes interposed by a semi-permeable membrane within a vessel for creating a first passageway and a second passageway, an anode electrode of the pair of electrodes disposed in the first passageway, cathode electrode of the pair of electrodes disposed in the second passageway; flowing the carrier fluid through the vessel; applying an electric potential to the pair of electrodes to produce an oxidative acidic fluid, a reductive alkaline fluid, and anodic gases in the container; removing the fluids and gases from the vessel; mixing a portion of the anodic gases with the reductive alkaline fluid to produce a hypochlorite solution; and mixing a chlorite brine with the hypochlorite solution, followed by the introduction of additional oxidative acidic fluid to release the biocide.

Abstract: The present disclosure provides an apparatus and a method for recovery of valuable metals. The apparatus includes an electrolytic chlorine producing bath, a dissolution bath disposed at a rear side of the electrolytic chlorine producing bath to perform leaching of a valuable metal content, a gas supplier connected to the dissolution bath to supply a carrier gas, a collection bath disposed at the rear side of the dissolution bath to collect a volatile material, a separation bath separating and purifying a leaching reactant generated in the dissolution bath, and chlorine and sodium hydroxide recirculation lines connecting the electrolytic chlorine producing bath, the dissolution bath and the separation bath. The apparatus permits recovery of valuable metals according to characteristics of the valuable metal, and the chlorine and sodium hydroxide recirculation lines of the apparatus provides optimized recovery rate and efficiency, thereby realizing economic feasibility.

Abstract: A method for concentrating an aqueous caustic alkali produced by a membrane cell process by using a single or multiple effect evaporator system in which the vapor flows in a counter direction to the aqueous caustic alkali flow and the heat recovered from the catholyte circulation line is used as part of the concentration process. In one embodiment, a catholyte heat recovery heat exchanger and evaporation chamber are located after the last effect of a multiple effect evaporator system. In another embodiment, the catholyte heat recovery heat exchanger and evaporation chamber are located prior to the single or multiple effect evaporator system. In yet another embodiment, the catholyte heat recovery process is used in conjunction with additional heat exchanger processes to further concentrate the final product as desired.

Abstract: An onsite integrated production factory having an electrolytic plant, an ethanol plant, a vegetable plant, a culturing plant, and a power generation unit. The onsite integrated production facility is arranged so that fresh water, sulfuric acid or caustic soda produced by and received from the electrolytic plant is used in the ethanol plant to produce and output oxalic acid, sodium oxalate, fuel bioethanol. The oxalic acid or sodium oxalate produced in and received from the ethanol plant is used for removing calcium contained in the sea water in the electrolytic plant. The vegetable plant produces vegetables for generation and outputting of oxygen by receiving the carbon dioxide generated during the fermentation process in the ethanol plant and fresh water from the electrolytic plant. The culturing plant has a fishery farm or reef for using the oxygen generated in the vegetable plant.

Abstract: Aqueous composition containing at least one salt in an amount of at least 30 g/kg of composition, of which the total organic carbon content is at least 1 ?g of C/l and at most 5 g of C/l of composition and which contains at least one carboxylic acid.

Abstract: Chlorine with a low bromine content is produced by electrolyzing brine to produce gaseous chlorine, alkali metal hydroxide and hydrogen, separating the gaseous chlorine from the electrolyte (anolyte in the case of the membrane process), directing electrolyte to a primary dechlorination step using hydrochloric acid to remove gaseous chlorine therefrom, optionally directing depleted electrolyte (anolyte in the case of the membrane process) from the primary dechlorination step to a secondary dechlorination step using a reducing agent for chlorine and oxychlorine species, and recycling dechlorinated depleted electrolyte (anolyte in the case of the membrane process) to salt dissolvers to prepare brine for electrolysis. At least part of the gaseous chlorine generated in the primary dechlorination step is not combined with gaseous chlorine generated in the electrolysis step.

Abstract: An apparatus for the electrolytic splitting of water into hydrogen and/or oxygen, the apparatus comprising: (i) at least one lithographically-patternable substrate having a surface; (ii) a plurality of microscaled catalytic electrodes embedded in said surface; (iii) at least one counter electrode in proximity to but not on said surface; (iv) means for collecting evolved hydrogen and/or oxygen gas; (v) electrical powering means for applying a voltage across said plurality of microscaled catalytic electrodes and said at least one counter electrode; and (vi) a container for holding an aqueous electrolyte and housing said plurality of microscaled catalytic electrodes and said at least one counter electrode. Electrolytic processes using the above electrolytic apparatus or functional mimics thereof are also described.

Abstract: [Problems] The liquid pressure of an anode chamber in a two-chamber ion exchange membrane electrolytic cell using a gas diffusion electrode are different among one another depending on depths so that the liquid pressures are applied on an anode or an ion exchange membrane, thereby introducing damage or deformation of the elements. [Means for Solving] A cushion material 10 is accommodated between a cathode gas chamber back plate 9 and a gas diffusion electrode 7 of an ion exchange membrane electrolytic cell 1 such that a repulsive force of the cushion material at the bottom part of the cathode gas chamber is larger than that at the top part. The excessive pressure applied to an ion exchange membrane is suppressed to prevent the generation of scratches or the like by decreasing the repulsive force of the cushion material toward the top in accordance with a differential pressure between an anode chamber pressure and a cathode gas chamber pressure.

Abstract: Using electric power obtained by marine wind force and a tide, sea water is electrolyzed to produce fresh water, sodium, magnesium, calcium, potassium, caustic soda, chlorine, hydrochloric acid, sulfuric acid, hydrogen, oxygen or the like, at the same time, unloaded malts, saw dust and the like are fermented to brew ethanol, carbon dioxide generated here is used for photosynthesis to culture vegetables and oxygen generated here is supplied to a fish preserve and an under reef where fish live to culture fishes and also returned to sea water dropped in the concentration of oxygen to suppress the generation of a red tide.

Abstract: Disclosed is a process for manufacturing bleach (or sodium hypochlorite) and caustic potash (or KOH) without the need for shipping or storing chlorine gas. Specifically, the present invention relates to the manufacture of potassium hydroxide and chlorine gas, through several process options, for the manufacture of sodium hypochlorite (or bleach), hydrochloric acid (HCl) and/or other chlorinated compounds. The disclosed process allows operating flexibility based on chlorine demand, reduces capital costs, and eliminates the need for the transportation and storage of chlorine gas.

Abstract: Processes are provided for conjointly producing Br2, a concentrated aqueous solution containing CaCI2, and Cl2 from an aqueous HBr-rich stream and a feed brine dilute in CaCI2 that comprises NaCI. Such processes can comprise feeding the aqueous HBr-rich stream and the feed brine to a tower, oxidizing bromide moieties within the tower with Cl2 from a Cl2 source, at least a portion of which is produced according to this invention, to produce Br2, recovering Br2 from the tower, removing a bromide-depleted bottoms from the tower, such bottoms containing HCI, adding a Ca++ source to the bromide-depleted bottoms to convert substantially all of the HCI in the bottoms to CaCI2, as necessary, removing water from the treated bottoms to produce the concentrated aqueous solution, producing Cl2 and caustics from residual chlorides such as NaCI, and using at least a portion of the thus produced Cl2 in the Cl2 source.

Abstract: Electrolysis cell for membrane-supported electrolysis, comprising an oxygen-consuming cathode.

Abstract: An integrated process separates salts from salty waters and electrolyzes the salts to produce chlorine products such as chlorine, hypochlorites, chlorates and/or caustic soda.

Abstract: Described is a method for improving the operation of an electrolytic cell having an anolyte compartment, a catholyte compartment and a synthetic diaphragm separating the compartments, wherein liquid anolyte is introduced into the anolyte compartment and flows through the diaphragm into the catholyte compartment, which method involves introducing particulate material comprising halocarbon polymer short fiber, e.g., fluorocarbon polymer short fiber, into the anolyte compartment in amounts sufficient to lower the flow of liquid anolyte through the diaphragm into the catholyte compartment. In the case of an electrolytic cell wherein aqueous alkali metal chloride, e.g.

Abstract: Disclosed is a process for manufacturing bleach (or sodium hypochlorite) and caustic potash (or KOH) without the need for shipping or storing chlorine gas. Specifically, the present invention relates to the manufacture of potassium hydroxide and chlorine gas, through several process options, for the manufacture of sodium hypochlorite (or bleach), hydrochloric acid (HCl) and/or other chlorinated compounds. The disclosed process allows operating flexibility based on chlorine demand, reduces capital costs and eliminates the need for the transportation and storage of chlorine gas.

Abstract: Method for purifying an aqueous composition by removing silicon therefrom, according to which a compound comprising aluminum is added to the aqueous composition in order to obtain a molar aluminum content greater than the molar silicon content in said composition, the pH of the composition is controlled and maintained at a value higher than or equal to 8 and lower than or equal to 10, and the precipitate formed is separated from the aqueous suspension obtained.

Abstract: Apparatuses and methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, and mixing the hydroxide with the gas stream to produce carbonate and/or bicarbonate. Some of the apparatuses of the present invention comprise an electrolysis chamber for providing hydroxide and mixing equipment for mixing the hydroxide with a gas stream including carbon dioxide to form an admixture including carbonate and/or bicarbonate.

Abstract: An aqueous solution of sodium chloride is electrolyzed in a cell (1) with an ion permselective membrane to produce, on the one hand, chlorine (16) which is converted in a chlorine production unit (6) and, on the other, an aqueous sodium hydroxide solution (19), which is carbonated using a flue gas (13) from an electricity and steam cogeneration unit (5), and the resulting carbonated solution (18) is evaporated to produce sodium carbonate crystals (21).

Abstract: The invention relates to a process for preparing methylenediphenyl diisocyanates which comprises at least the steps: A) reaction of aniline with formaldehyde in the presence of hydrochloric acid as catalyst to give a mixture of diamines and polyamines of the diphenylmethane series (MDA) and subsequent at least partial neutralization of the hydrochloric acid by means of alkali metal hydroxide, B) reaction of the mixture of diamines and polyamines of the diphenylmethane series obtained in step A) with phosgene to give a mixture of diisocyanates and polyisocyanates of the diphenylmethane series (MDI) and hydrogen chloride, wherein C) the hydrochloric acid which has been neutralized in step A) is separated off in the form of a solution containing alkali metal chloride and is subsequently at least partly fed to an electrochemical oxidation to form chlorine, alkali metal hydroxide and optionally hydrogen and D) at least part of the chlorine produced in step C) is used for preparing the phosgene used in step B).

Abstract: The invention relates to a diaphragm electrolytic cell, for the production of chlorine and caustic soda having superimposed modules, and a method for increasing the electrodic surface of a diaphragm electrolytic cell constituted by a module of interdigitated anodes and cathodes which foresees an additional cell module having the same geometry as that of the original cell. The additional module is hydraulically connected in series and electrically connected in parallel to the existing module.

Abstract: A method for the electrolysis of aqueous solutions of hydrogen chloride in order to produce chlorine, characterized in that the following process parameters are maintained for initial operation: the anode half-element is filled with a 5 to 20% strength by weight hydrochloric acid, the concentration of the hydrochloric acid is more than 5% by weight during initial operation, the volumetric flow of the hydrochloric acid through the anode half-element is set in such a way that, at the start of electrolysis, the velocity of the hydrochloric acid in the anode space is from 0.05 cm/s to 0.15 cm/s, the electrolysis is started with a current density of 0.5 to 2 kA/m2, and the current density is then increased continuously or discontinuously until the desired current density is reached.

Abstract: The invention describes a process for the electrolysis of an aqueous solution of alkali metal chloride, in particular sodium chloride, by the membrane process with an aqueous solution of alkali metal hydroxide, in particular sodium hydroxide, as catholyte, where the temperature of the alkali metal chloride solution in the anode half-element and/or the volume flow rate of the alkali metal chloride solution in the anode half-element are set in such a way that the difference between the temperature of the alkali metal hydroxide solution at the entry into the cathode half-element and the temperature of the alkali metal hydroxide solution at the exit from the cathode half-element are not greater than 15° C.

Abstract: A method of generating basic hydrogen peroxide (BHP) fuel for a chemical oxygen-iodine laser (COIL) using stored alkali chloride, typically potassium chloride, and water. The alkali chloride and water are mixed to form a saturated or nearly saturated aqueous salt solution for use as an anolyte feed to a chlor-alkali cell. The chlor-alkali cell generates alkali hydroxide, hydrogen, and chlorine. Water and oxygen are reacted to form peroxide which is combined with the alkali hydroxide from the chlor-alkali cell to form a dilute solution of BHP, a mixture of hydrogen peroxide and alkali hydroxide, which dissociates into O2H? and ?OH. The BHP is concentrated and the molar ratio of hydrogen peroxide to alkali hydroxide is adjusted to 1:1 before the BHP is supplied to a COIL apparatus as fuel for the lasing process.

Abstract: A washing, cleaning and sterilizing solution is produced by electrolyzing an electrolyte solution composed of mixed caustic soda and salt in an electrolyzer. The solution is used as it is or diluted with tap water or non-potable water. The solution is applicable to washing, cleaning and sterilizing metal goods, medical instruments, nursing products, foodstuff, farm products, marine products, dishes, cooking utensils, plastic goods, surrounding, facilities, fiber products, machine parts, machine goods, various containers, electrical communication components, vehicles, or the like.

Abstract: The present invention relates to an electrolyte composition for electrolysis of brine, a method for electrolysis of brine, and sodium hydroxide prepared therefrom, and particularly to an electrolyte composition for electrolysis of brine, a method for electrolysis of brine comprising injecting brine and pure water respectively to a cation chamber and an anion chamber divided by a separation membrane installed in an electrolytic cell through a brine injection tube and a pure water injection tube, and applying a power source to an anode plate and a cathode plate installed in the cation chamber and anion chamber to separate produced chloride gas, hydrogen gas, and a sodium hydroxide aqueous solution characterized in that an aqueous solution of a platinum compound is injected into the anion chamber through the pure water injection tube, and sodium hydroxide prepared therefrom.

Abstract: A method for the reduction of soluble aluminum species in an evaporated salt alkali metal halide brine containing up to 500 ppb aluminum species to provide a brine feedstock suitable for use in a chlor-alkali membrane cell process, said method comprising treating said brine with a magnesium salt in an amount to provide a Mg to Al molar ratio selected from 5-20 to 1 at a Mg concentration selected from 0.5-10 ppm, and sufficient alkali metal hydroxide to provide an excess alkalinity concentration of between 0.1-0.5 g/L alkali metal hydroxide to effect precipitation of a magnesium aluminum hydroxide complex; and removing said complex to provide said brine feedstock.

Abstract: An electrolytic cell for producing a chlor-alkali including at least two electrodes in reactive contact with an aqueous liquid containing a chloride salt, wherein at least one of the electrodes is within a magnetic field is described herein.

Abstract: A method of generating basic hydrogen peroxide (BHP) fuel for a chemical oxygen-iodine laser (COIL) using stored alkali chloride, typically potassium chloride, and water. The alkali chloride and water are mixed to form a saturated or nearly saturated aqueous salt solution for use as an anolyte feed to a chlor-alkali cell. The chlor-alkali cell generates alkali hydroxide, hydrogen, and chlorine. Water and oxygen are reacted to form peroxide which is combined with the alkali hydroxide from the chlor-alkali cell to form a dilute solution of BHP, a mixture of hydrogen peroxide and alkali hydroxide, which dissociates into O2H− and −OH. The BHP is concentrated and the molar ratio of hydrogen peroxide to alkali hydroxide is adjusted to 1:1 before the BHP is supplied to a COIL apparatus as fuel for the lasing process.

Abstract: An on-site apparatus and method for preparing aqueous cleaning compositions, including an electrolytic cell for producing and dispensing chlorine and sodium hydroxide for use in various cleaning and/or sanitizing formulations at the point of use.

Abstract: The present invention relates to a method of increasing the concentration of dilute brine in NaCl electrolysis plants using the membrane process, wherein the NaCl required is stored in a mass flow silo with supernatant liquid and is fed continuously from there to the quick dissolver.

Abstract: Provided is a process which permits, upon preparation of chlorine and a caustic alkali by electrolyzing an aqueous alkali chloride solution in an ion-exchange-membrane-method alkali chloride electrolytic cell equipped with a gas diffusion cathode, decrease of an excess ratio of an oxygen containing gas to be fed newly to the gas diffusion cathode and facilitates temperature control of the electrolytic cell. A process for electrolyzing an alkali chloride comprising: introducing saline water into an anode chamber of an ion-exchange-membrane-method alkali chloride electrolytic cell equipped with a gas diffusion cathode; and introducing an oxygen-containing gas into a gas chamber of a gas diffusion cathode, to thereby obtain chlorine in the anode chamber and an aqueous caustic alkali solution in the cathode chamber.

Abstract: A method of operating an alkali chloride electrolytic cell, comprising: providing an alkali chloride electrolytic cell comprising a gas diffusion cathode and a cation-exchange membrane, the gas diffusion cathode and cation-exchange membrane defining a caustic chamber; allowing a caustic alkali aqueous solution to flow in the caustic chamber at a linear velocity of at least 1 cm/sec.

Abstract: The present invention pertains to electrolytic diaphragm cells, particularly for the electrolysis of brine to produce chlorine and caustic. The innovation resides generally in the discovery that electrolytic cell operation can be desirably enhanced by compressing the diaphragm between anode and cathode. This compression of the diaphragm reduces the diaphragm thickness from an original thickness, e.g., from an original thickness of a diaphragm freshly deposited on a cathode. The reduced thickness of the diaphragm provides for cell operation that is less than zero gap operation. By maintaining the diaphragm under compression and in a reduced thickness, the cell operates with a narrower interelectrode gap and consequently at a desirably reduced cell voltage.

Abstract: This invention relates to methods, systems and installations for concentrating depleted brine produced by the electrolytic decomposition of concentrated brine in chlor-alkali membrane cells and to the efficient use of power, steam and brine. More particularly, this invention relates to the use of depleted brine directly into evaporation systems, which are used to concentrate the brine for reuse in membrane cells or other processes. This invention employs the phenomena that a week unsaturated brine boiling under reduced pressure has a lower boiling point rise (BPR) than a saturated brine boiling at the same or higher pressure. The concentration of depleted brine at a lower boiling point rise improves the operating efficiency of either mechanical vapor recompression and/or steam jet thermocompression. Further, this invention allows for concentrating the depleted brine at temperatures low enough to utilize plastic materials of construction.

Abstract: A method to prevent cladding or plating of metals, such as nickel or iron in a continuous production of alkali metal hydroxides which involves several steps: electrolyzing an aqueous alkali metal salt solution forming hydrogen, chlorine and an at least 10% caustic solution at a temperature of from about 75 to about 100 F; and treating said at least 10% caustic solution to create a more concentrated caustic solution while continuously and magnetically removing up to 33% of the metals present in the solution from the at least 10% caustic solution using a first magnet prior to evaporation, flashing and cooling of the at least 10% caustic solution, and then magnetically removing an additional amount of metals from the resultant more concentrated caustic solution again with a second magnet prior to filtration of the more concentrated caustic solution.

Abstract: A process for adjusting the pH of an aqueous flowable fluid includes an electrochemical mechanism for adjusting the pH of an aqueous flowable fluid and a mechanism for then electrochemically stabilizing the adjusted pH of the fluid. A device for performing the process is also included. The device includes an inlet and a channel in fluid communication with the inlet. The channel has the appearance and properties of a U-shaped connected vessel. The U-shaped connected vessel includes an inlet accumulating passage in fluid communication with an active zone between two spaced electrodes wherein the active zone has a small volume relative to the passage for accelerating fluid flow from the passage through the active zone complying with the physics of connected vessels.

Abstract: In removal of sulfate groups and chlorate groups from brine used for electrolysis, concentrated brine used in an electrolysis process or dilute brine whose concentration is decreased by electrolysis is fed to an anode chamber divided by a cation exchange membrane in a brine treating electrolyzer, where the concentrated or dilute brine is electrolyzed to recover chloride ions therein. The concentrated brine is electrolyzed at a rate of decomposition of salt higher than that in the ion exchange membrane electrolysis process of brine. Thereafter, the concentrated or dilute brine is discharged out of the electrolysis process.

Abstract: The present invention relates to a method to control of the presence of nickel and/or iron in a caustic solution using at least two magnets to remove about one third of the nickel and/or iron present in a caustic solution. The method involves passing cell liquor through a first magnet at a flow rate of about 600-900 gallons per minutes removing a significant amount of nickel and/or iron from the cell liquor forming first fluid, then evaporating a significant amount of water out of that first fluid and raising the temperature of that first fluid to above 330 F., then cooling the more concentrated caustic solution to a temperature of between about 75 and 100 F.

Abstract: Electrolysing an aqueous solution of sodium chloride by means of a cell comprising a cation-exchange membrane which divides the cell into an anode compartment and an cathode compartment in which the said cathode is placed directly against the cation-exchange membrane, the said cathode compartment being supplied with a humidified gas containing oxygen, characterized in that, in order to obtain a concentration by weight of sodium hydroxide between the cation-exchange membrane and the cathode of less than 38.8%, use is made of an aqueous solution of sodium chloride (anolyte) having a concentration by weight of sodium chloride of less than 200 g/l, and in that the water humidifying the gas containing oxygen is in the form of water vapour.