Abstract: Provided are an electrolyzer having excellent durability against reverse current. The electrolyzer 300 includes an anode 314, an anode chamber 310 housing the anode 314, a cathode 330, a cathode chamber 320 housing the cathode 330, and a diaphragm that separates the anode chamber 310 and the cathode chamber 320, wherein a reverse current absorption body 334 formed of a sintered compact containing nickel is disposed in at least one of an inside of the cathode chamber 320 and an inside of the anode chamber 310, and the reverse current absorption body 334 is not directly coupled to the cathode 330 and the anode 314 but is electrically connected to at least one of the cathode 330 and the anode 314.

Abstract: Provided are an electrode for electrolysis having excellent durability against reverse current, and a method that enables production of the electrode for electrolysis at low cost. The electrode for electrolysis 130 includes a conductive substrate 132 on which a catalyst layer is formed, and a reverse current absorption body 134 that is coupled to the conductive substrate 132 in a detachable manner, wherein the reverse current absorption body 134 is formed from a sintered compact containing nickel. The method for producing the electrode for electrolysis 130 includes a sintered compact formation step of obtaining the sintered compact by sintering a raw material powder composed of any one of Raney nickel alloy particles containing nickel and an alkali-soluble metal element, metallic nickel particles, and a mixture of Raney nickel alloy particles and metallic nickel particles, and a coupling step of coupling the sintered compact to the conductive substrate 132.

Abstract: Provided are an electrode for electrolysis having excellent durability against reverse current, and a method that enables production of the electrode for electrolysis at low cost. The electrode for electrolysis 130 includes a conductive substrate 132 on which a catalyst layer is formed, and a reverse current absorption body 134 that is coupled to the conductive substrate 132 in a detachable manner, wherein the reverse current absorption body 134 is formed from a sintered compact containing nickel. The method for producing the electrode for electrolysis 130 includes a sintered compact formation step of obtaining the sintered compact by sintering a raw material powder composed of any one of Raney nickel alloy particles containing nickel and an alkali-soluble metal element, metallic nickel particles, and a mixture of Raney nickel alloy particles and metallic nickel particles, and a coupling step of coupling the sintered compact to the conductive substrate 132.

Abstract: Provided are an electrolyzer having excellent durability against reverse current. The electrolyzer 300 includes an anode 314, an anode chamber 310 housing the anode 314, a cathode 330, a cathode chamber 320 housing the cathode 330, and a diaphragm that separates the anode chamber 310 and the cathode chamber 320, wherein a reverse current absorption body 334 formed of a sintered compact containing nickel is disposed in at least one of an inside of the cathode chamber 320 and an inside of the anode chamber 310, and the reverse current absorption body 334 is not directly coupled to the cathode 330 and the anode 314 but is electrically connected to at least one of the cathode 330 and the anode 314.

Abstract: A continuous cooking process making use of a digester, which includes therein, from a top toward a bottom of the digester, a top zone, an upper cooking zone, a lower cooking zone and a cooking/washing zone and also includes strainers provided at the bottom of the respective zones and wherein a cooking black liquor extracted from at least one of the strainers is discharged to outside a digestion system, a process for cooking a lignocellulose characterized by feeding, upstream of the top of the digester, a first cooking liquor containing an alkaline cooking liquor having a specified composition, feeding a second cooking liquor of an alkaline cooking liquor made mainly of sodium hydroxide to the upper cooking zone, and feeding a third cooking liquor of an alkaline cooking liquor similar to the second cooking liquor to the cooking/washing zone.

Abstract: The present invention provides an ozone generator comprising an anode and a cathode provided on each side of a fluororesin type cation exchange membrane, the anode being a conductive diamond electrode having conductive diamond on the surface, wherein water is supplied to an anode compartment, DC current is supplied between the anode and the cathode to electrolyze water to evolve ozone from the anode compartment and hydrogen from a cathode compartment, the conductive diamond electrode comprising a substrate having a plurality of convexo-concave and a conductive diamond film coated on the surface of the substrate is applied as the conductive diamond electrode, and a close packed layer of ion exchange resin particles or the fluororesin type cation exchange membrane with notch is closely adhered to the surface of the anode side of the fluororesin type cation exchange membrane.

Abstract: The present invention provides an ozone generator comprising an anode and a cathode provided on each side of a fluororesin type cation exchange membrane, the anode being a conductive diamond electrode having conductive diamond on the surface, wherein water is supplied to an anode compartment, DC current is supplied between the anode and the cathode to electrolyze water to evolve ozone from the anode compartment and hydrogen from a cathode compartment, the conductive diamond electrode comprising a substrate having a plurality of convexo-concave and a conductive diamond film coated on the surface of the substrate is applied as the conductive diamond electrode, and a close packed layer of ion exchange resin particles or the fluororesin type cation exchange membrane with notch is closely adhered to the surface of the anode side of the fluororesin type cation exchange membrane.

Abstract: The cleaning method by electrolytic sulfuric acid and the manufacturing method of semiconductor device comprising: the process in which the first sulfuric acid solution is supplied from outside to the sulfuric acid electrolytic cell to form the first electrolytic sulfuric acid containing oxidizing agent in the sulfuric acid electrolytic cell; the process in which the second sulfuric acid solution, which is higher in concentration than said the first sulfuric acid solution previously supplied, is supplied from outside to said sulfuric acid electrolytic cell; said the second sulfuric acid solution and the first electrolytic sulfuric acid are mixed in said sulfuric acid electrolytic cell; and electrolysis is performed to form the cleaning solution comprising the second electrolytic sulfuric acid containing sulfuric acid and oxidation agent in said sulfuric acid electrolytic cell and the process in which cleaning treatment is performed for the cleaning object with said cleaning solution.

Abstract: In a cooking process of a lignocellulose material, pulp yield can be improved at the same Kappa number and an effective alkali addition rate can be reduced at the same Kappa number.

Abstract: The invention provides an ion exchange membrane electrolytic process unlikely to undergo any current density drop even when brine having a concentration lower than usual. Electrolysis occurs while the concentration of an aqueous solution of an alkaline metal chloride in an anode chamber partitioned by a cation exchange membrane is set at 2.7 mol/l to 3.3 mol/l, and a gap is provided between the cation exchange membrane and the anode.

Abstract: The cleaning method by electrolytic sulfuric acid and the manufacturing method of semiconductor device comprising: the process in which the first sulfuric acid solution is supplied from outside to the sulfuric acid electrolytic cell to form the first electrolytic sulfuric acid containing oxidizing agent in the sulfuric acid electrolytic cell; the process in which the second sulfuric acid solution, which is higher in concentration than said the first sulfuric acid solution previously supplied, is supplied from outside to said sulfuric acid electrolytic cell; said the second sulfuric acid solution and the first electrolytic sulfuric acid are mixed in said sulfuric acid electrolytic cell; and electrolysis is performed to form the cleaning solution comprising the second electrolytic sulfuric acid containing sulfuric acid and oxidation agent in said sulfuric acid electrolytic cell and the process in which cleaning treatment is performed for the cleaning object with said cleaning solution.

Abstract: The invention provides an ion exchange membrane electrolytic process unlikely to undergo any current density drop even when brine having a concentration lower than usual. Electrolysis occurs while the concentration of an aqueous solution of an alkaline metal chloride in an anode chamber partitioned by a cation exchange membrane is set at 2.7 mol/l to 3.3 mol/l, and a gap is provided between the cation exchange membrane and the anode.

Abstract: In a method of removing impurities, especially iodine and/or silica ions, from a salt solution to be used for electrolysis, the salt solution and zirconium hydroxide are brought into contact with each other under acidic conditions, and the zirconium hydroxide adsorbs the impurities. Thereafter, the zirconium hydroxide containing the adsorbed impurities is brought into contact with an aqueous solution at a higher pH value to desorb the impurities from the zirconium hydroxide, thereby enabling the zirconium hydroxide to be recycled.

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: CMPO is safely, reliably and rapidly decomposed under mild conditions. A CMPO-containing substance is emulsified in an electrolyte comprising an oxidation promoter (silver ion) by an emulsifier in an emulsifying tank, this electrolyte comprising the CMPO-containing substance is supplied to an anode chamber, and an electrolytic oxidation reaction is performed by passing an electric current. By emulsifying the CMPO-containing substance, the surface area of CMPO in contact with electrolyte is increased, and electrolytic decomposition is thereby promoted. As sufficient CMPO decomposition is not obtained by passing the emulsion only once through an electrolysis tank 1, a batch oxidation method is employed wherein an anolyte is recirculated by a recirculating pump 3a through the anode chamber, a constant temperature bath 7a and an emulsifying tank 6, so that electrolysis is performed with the CMPO-containing substance permanently emulsified in the electrolyte.

Abstract: In an activated cathode and a method for manufacturing the activated cathode, a first layer which contains nickel or cobalt as a main component is formed on a metal substrate, and a second layer which contains platinum or ruthenium as a main component is formed on the first layer. It is preferable that the first layer is formed of Raney nickel and the second layer has a large cathode working area, or it is also preferable that the first layer is formed of nickel oxide or cobalt oxide, and the second layer is formed of fine platinum or ruthenium particles and has a large cathode working area.

Abstract: The present invention provides a method for manufacturing hypochlorite efficiently, using an anode, which has a coating containing palladium oxide by 10 to 45 weight %, ruthenium oxide by 15 to 45 weight %, titanium dioxide by 10 to 40 weight %, and platinum by 10 to 20 weight % as well as an oxide of at least one metal selected from cobalt, lanthanum, cerium or yttrium by 2 to 10 weight % being formed on a conductive base, and a cathode comprising a coating having low hydrogen overvoltage and covered with a reduction preventive film and being formed on a conductive base, and an aqueous solution of a chloride is electrolyzed without a diaphragm.

Abstract: A method for removing sulfate ions from an aqueous solution of an alkali metal chloride is disclosed, in which the aqueous solution of the alkali metal chloride containing sulfate ions and zirconium hydrous oxide are brought into contact with each other in a slurry form under acidic conditions to thereby cause the sulfate ions to be adsorbed to the zirconium hydrous oxide by an ion exchange reaction, the zirconium hydrous oxide adsorbing sulfate ions is separated from the aqueous solution and then dispersed in another aqueous liquid to thereby cause it to react with an alkali so as to cause sulfate ions to be desorbed into the aqueous liquid. According to this method, adsorption and desorption take place rapidly and efficiently.

Abstract: A method for controlling chlorates in an aqueous alkali metal hydroxide liquor produced by an ion exchange membrane electrolysis is provided, which comprises adding a reducing agent to brine to keep the concentration of chlorates to a specified value or less. The present invention provides an alkali metal hydroxide liquor with low content of chlorates.

Abstract: Disclosed is a method for preventing a low hydrogen overvoltage cathode from degradation in activity characterized by adding a reducing agent to a cathode compartment of an electrolytic cell which electrolysis an aqueous alkali metal halide solution. According to the invention, no degradation takes place even after repeated shutdown of operation.