Abstract: Provided are an anode for an ion exchange membrane electrolyzer which enables an aqueous solution of an alkali metal chloride to be electrolyzed at a lower voltage than a conventional anode and allows the concentration of an impurity gas included in an anode gas to be reduced and an ion exchange membrane electrolyzer using the same. The anode is an anode for an ion exchange membrane electrolyzer to be used in an ion exchange membrane electrolyzer that is separated by an ion exchange membrane into an anode chamber and a cathode chamber. The anode for an ion exchange membrane electrolyzer comprises at least one perforated flat metal plate 1 (expanded metal 1) and the thickness of the perforated flat metal plate 1 (expanded metal 1) ranges from 0.1 to 0.5 mm and the ratio of the short way SW to the long way LW (SW/LW) ranges from 0.45 to 0.55. The short way SW is preferably not more than 3.0 mm.

Abstract: To provide an electrolysis electrode having a more preferable shape in electrolyzing pure water, an alkali aqueous solution, or an aqueous solution of an alkali metal chloride at a lower voltage than ever before, and an electrolyzer using the same. An electrolysis electrode or the like including: a metal perforated plate having a value of Factor V of 40 or more represented by the formula: Factor V=Rs×Rc×F/100000, in which Rs is a planar direction surface area per unit area 1 dm2 [cm2/dm2], Rc is a thickness direction surface area per unit area 1 dm2 [cm2/dm2], and F is the number of mesh apertures per unit area 1 dm2 (fine degree) [number/dm2].

Abstract: A diaphragm includes a porous supporting body and a polymer porous membrane. When one of surfaces of the porous membrane is defined as a surface A, the other surface opposite to the surface A is defined as a surface B, a section of the porous membrane parallel to the surfaces A and B is defined as a section C, an average pore diameter on the surface A is defined as an average pore diameter DA, an average pore diameter on the surface B is defined as an average pore diameter DB, and an average pore diameter on the section C is defined as an average pore diameter DC, the average pore diameters DA and DB are substantially equal to each other, and the average pore diameter DC is larger than each of the average pore diameters DA and DB.

Abstract: Provided is a method of preventing reverse current flow through an ion exchange membrane electrolyzer, which method is capable of preventing a reverse current from being generated after stopping operation of the ion exchange membrane electrolyzer. A method of preventing reverse current flow through an ion exchange membrane electrolyzer 100, the ion exchange membrane electrolyzer 100 having an anode chamber 107 housing an anode, a cathode chamber 110 housing a cathode, an anode solution-supplying manifold 121 to feed anode solution to the anode chamber 107, and a cathode solution-supplying manifold 124 to feed cathode solution to the cathode chamber 110.

Abstract: A diaphragm includes a porous supporting body and a polymer porous membrane. When one of surfaces of the porous membrane is defined as a surface A, the other surface opposite to the surface A is defined as a surface B, a section of the porous membrane parallel to the surfaces A and B is defined as a section C, an average pore diameter on the surface A is defined as an average pore diameter DA, an average pore diameter on the surface B is defined as an average pore diameter DB, and an average pore diameter on the section C is defined as an average pore diameter DC, the average pore diameters DA and DB are substantially equal to each other, and the average pore diameter DC is larger than each of the average pore diameters DA and DB.

Abstract: Provided are an anode for an ion exchange membrane electrolyzer which enables an aqueous solution of an alkali metal chloride to be electrolyzed at a lower voltage than a conventional anode and allows the concentration of an impurity gas included in an anode gas to be reduced and an ion exchange membrane electrolyzer using the same. The anode is an anode for an ion exchange membrane electrolyzer to be used in an ion exchange membrane electrolyzer that is separated by an ion exchange membrane into an anode chamber and a cathode chamber. The anode for an ion exchange membrane electrolyzer comprises at least one perforated flat metal plate 1 (expanded metal 1) and the thickness of the perforated flat metal plate 1 (expanded metal 1) ranges from 0.1 to 0.5 mm and the ratio of the short way SW to the long way LW (SW/LW) ranges from 0.45 to 0.55. The short way SW is preferably not more than 3.0 mm.

Abstract: An alkaline water electrolysis diaphragm includes: a polymer porous layer containing at least one polymer compound selected from polyether sulfone having a contact angle of 20 to 90° and polysulfone having the contact angle of 20 to 90°; and an organic fiber fabric layer coupled to the polymer porous layer. The polyether sulfone having the contact angle of 20 to 90° is at least one polymer compound selected from the group made of polyether sulfone, hydrophilic polyether sulfone, cationic polyether sulfone, and cationic hydrophilic polyether sulfone. The polysulfone having the contact angle of 20 to 90° is at least one polymer compound selected from the group made of polysulfone, hydrophilic polysulfone, cationic polysulfone, and cationic hydrophilic polysulfone.

Abstract: Provided is a method of preventing reverse current flow through an ion exchange membrane electrolyzer, which method is capable of preventing a reverse current from being generated after stopping operation of the ion exchange membrane electrolyzer. A method of preventing reverse current flow through an ion exchange membrane electrolyzer 100, the ion exchange membrane electrolyzer 100 having an anode chamber 107 housing an anode, a cathode chamber 110 housing a cathode, an anode solution-supplying manifold 121 to feed anode solution to the anode chamber 107, and a cathode solution-supplying manifold 124 to feed cathode solution to the cathode chamber 110.

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: According to the system by the present invention, multiple numbers of grooves 13 are formed on the internal surface of said anode compartment frame 6 and said cathode compartment frame 12, an anolyte gas-liquid separation tower 4 to separate anolyte from ozone-containing gas generated from said anode compartment 1, being connected to said anode compartment 1 and a catholyte gas-liquid separation tower 5 to separate catholyte from hydrogen gas generated from said cathode compartment 2, being connected to said cathode compartment 2 are installed outside of said electrolytic cell 3 for ozone producing; achieving enhanced cooling effect of anolyte and catholyte and producing ozone gas at a high efficiency.

Abstract: In an ozone producing electrolytic cell for producing ozone gas by water electrolysis, said anode compartment 1, said cathode compartment 2, said anode compartment frame 6, said anode 8, said ion exchange membrane 9, said cathode 10, said current collector 11, and said cathode compartment frame 12 constituting the electrolytic cell for ozone production 3 are all in the same shape of square or rectangular; and multiple numbers of grooves 13 are formed on the internal surfaces of said anode compartment frame 6 and said cathode compartment frame 12, thereby reducing current density to suppress load on the electrolytic cell for ozone production, even under a given current value supplied to the electrolytic cells for producing ozone.

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.