Kernforschungsanlage Julich

Forschungszentrum Julich Gmbh

Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Herbert Neumeister

Bernd D Struck

Aristides Naoumidis

Leander Furst

Dagmar Boltersdorf

Robert Junginger

Arno Schirbach

Reinhold Flucht

Dieter Triefenbach

In an electrochemical cell arrangement for the deionization of aqueous solutions by ion exchange including cathode and anode chambers having electrodes disposed therein, a brine chamber is disposed between, and directly adjacent to, the cathode and anode chambers which are filled with anion and cation exchanger materials such that the electrodes are directly in contact therewith and means are provided for conducting the aqueous solution to be treated through the cathode and anode chambers and means for passing brine through the brine chamber to be charged therein by the ions removed from the aqueous solution in the cathode and anode chambers.

Electrolytic cell arrangement for the deionization of aqueous solutions

A cathode/membrane assembly for an electrolysis cell capable of producing hydrogen in a cathode compartment, utilizes as the cathode material on a proton-permeable solid-electrolite ion-exchange membrane, a layer of porous graphite in the form of carbonaceous fibers coated with tungsten carbide. The graphite felt can be impregnated with an aqueous solution of para-ammoniumtungstate or with an alcoholic solution of tungsten hexachloride and the tungsten compounds are then converted to the tungsten oxides. The tungsten oxide coated graphite felt is then subjected to carburization at a temperature of 620.degree. to 950.degree. C. in a carburizing atmosphere, preferably a flowing CO/CO.sub.2 mixture.

Cathode/membrane assembly and method of making same

A process is disclosed for the production of a tungsten carbide-activated electrode, particularly an electrode which is utilizable as a cathode, and which consists of an electrically-conductive substrate with an active surface layer of tungsten carbide. The tungsten carbide is adhesively bonded through chemical reaction to the surface of a substrate which is constituted of graphite or a graphite-like material. The graphite-like material is a graphite binder mixture, whose binder material components, other than the graphitic filler granules, are only carbonized, and may not be completely graphited.

Process for production of a tungsten carbide-activated electrode

The production of hydrogen by electrolysis in a cell, in which the anode electrolyte contains sulfur dioxide as well as sulfuric acid and an intermediate chamber separated from the anode and cathode chambers by cation-exchanger membranes is provided through which an electrolyte flows in order to prevent sulfur dioxide from reaching the cathode chamber is greatly improved by using as the anode side membrane a cation-exchanger in which a polyvinyl chloride skeleton is combined with a polymer of styrol and divinyl benzol to which sulfonic acid groups have been attached, such a membrane having a very low resistivity, thus reducing the necessary electrolysis voltage. Such a membrane also loses conductivity with increasing sulfuric acid concentration at a lower rate than membranes previously used in such an electrolysis process and permits a higher sulfuric acid concentration in the anode electrolyte. The improvement on the anode side makes possible the operation of the cathode at low sulfuric acid electrolyte concentration, below 20 or even 10% by weight. Through-flow electrodes of porous graphite encased except on the membrane side by impermeable graphite further improve the operation of the process, especially if they fill the electrolyte chamber right up to the membrane.

Electrolysis cell and method for electrolytic production of hydrogen

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Julich, Germany

Herbert Neumeister