An electrolysis cell comprising a housing containing a plurality of alternating anode units and cathode units and an ion permeable membrane sheet disposed therebetween and having in direct contact with the opposite sides of the membrane sheet a porous anode and a porous cathode, said cathode units comprising a pair of spaced foraminous cathodes of the same polarity forming a space for catholyte therebetween and means for flowing aqueous electrolyte through the catholyte space of the cathode unit and means for removing electrolysis products, the anode units comprising a pair of spaced foraminous anodes forming a space for anolyte therebetween, means for flowing aqueous halide solution through the said anolyte space and means for removing electrolysis products therefrom and means for uniformly compressing the units and membranes together and to a novel method of generating halogens by electrolysis of aqueous halide solutions.

Novel electrolysis cell

Chlorine is generated by electrolyzing aqueous alkali metal chloride in a cell wherein the anode and cathode are separated by and in contact with an ion exchange diaphragm and wherein the anode and/or cathode contains particles of an electroconductive catalytic material along with particles of an electroconductive extender bonded to the membrane.

Production of halogens by electrolysis of alkali metal halides in an electrolysis cell having catalytic electrodes bonded to the surface of a solid polymer electrolyte membrane

The invention describes a pressurized, three compartment membrane cell for the electrolyzing aqueous alkali metal halides at low cell voltages and with high cathodic current efficiencies. Unitary electrode-electrolyte structures, in the form electrochemically active electrodes physically bonded to ion transporting permselective membranes divide the cell into anode, cathode and buffer compartments. The buffer compartment feed is pressurized to maintain at a positive pressure differential with respect to the anode and cathode compartment feeds. The flexible unitary electrode-membrane electrolytes are forced outwardly against electronically conductive anode and cathode current collectors to provide uniform, constant and controllable contact between the bonded electrodes and thereby minimizing ohmic losses. A three compartment cell operated in this fashion not only minimizes the voltage required to electrolyze the halide solution, but also increases the cathodic current efficiency at high caustic concentrations by providing multiple hydroxide rejection stages in a single cell process. The improvement in cathodic current efficiency is realized by forming a lower caustic concentration in the buffer compartment than in the cathode compartment thereby reducing backmigration of OH- ions into the anode compartment.

Electrolysis of alkali metal halides in a three compartment cell with self-pressurized buffer compartment

An electrolytic cell comprises an anode and a cathode which are partitioned by an ion exchange membrane having at least one roughened surface which contacts with or closes in a distance of up to 20 mm to a corresponding electrode.

Ion exchange membrane cell and electrolytic process using thereof

An electrolytic cell for the electrolysis of aqueous solutions to produce gaseous products is comprised of a housing, a separator traversing said housing to form an anode compartment and a cathode compartment, an anode in the anode compartment, a cathode in the cathode compartment, means for introducing an electrolyte into and removing said electrolyte from said anode compartment, an outlet for gaseous products in the anode compartment, means for introducing a liquid into and removing a liquid from the cathode compartment, and an outlet for gaseous products in the cathode compartment. The electrolytic cell has at least one of the anode and the cathode comprising a porous electrode having a porosity in the range of from about 30 to about 98 percent, the porous electrode having a first portion in direct contact with the separator and a second portion spaced apart from the separator, the second portion being closer to said outlets for gaseous products than said first portion. The electrolytic cell operates at reduced cell voltages with improved release of gas bubbles formed during electrolysis and improved liquid circulation through the porous electrode.

V-Shaped sandwich-type cell with reticulate electodes

An improved anode structure for a chlor-alkali type diaphragm cell wherein the anode is a porous, valve metal, e.g., titanium, anode having on one side a coating of a noble metal or noble metal oxide and on the uncoated side a membrane composed essentially of a cation-active permselective material which is substantially impervious to liquids and gases. The membrane covered surface is disposed spaced from but facing the cathode member. Anodes of this improved structure give minimum cell voltage and a surprisingly reduced consumption rate of the noble metal or oxide coating.

Coating metal anodes to decrease consumption rates

An electrolytic cell suitable for use in electrolyzing ionizable chemical compounds, particularly alkali metal halide brines and hydrohalic acids, which comprises a cell body having an anode compartment containing a porous anode and a cathode compartment containing a cathode said compartments being separated from each other by a prestretched, taut membrane barrier which is substantially impervious to gases and liquids and which is selected from a hydrolyzed copolymer of a perfluorinated hydrocarbon and a sulfonated perfluorinated hydrocarbon and a sulfonated perfluorovinyl ether, and a sulfostyrenated perfluorinated ethylene propylene polymer, said barrier being pretreated by hydrolyzing and stretching prior to insertion in the cell. Such cells can be operated at constant low voltage, and are not subject to erratic operating voltages which are due, in part at least, to the accumulation of gases between the anode and diaphragm.

Cook Edward H

Papers

Coating metal anodes to decrease consumption rates

Electrolytic cell utilizing pretreated semi-permeable membranes