Bayer Aktiengesellschaft

Bayer Materialscience Ag

Other

De Nora Elettrodi S.p.a

Bayer Intellectual Property Gmbh

Covestro Deutschland Ag

Industrie De Nora S.p.a.

De Nora Deutschland Gmbh

Fritz Gestermann

Hans-Dieter Pinter

Andreas Bulan

Hans-Ulrich Dummersdorf

Franz-Rudolf Minz

Gerd Speer

Helmut Waldmann

Peter Fabian

Helmut Harle

Walter Hansen

Heiko Herold

Walter Klesper

Robert J Allen

Rainer Weber

Emory Sayre De Castro

Volker Michele

Alfred Soppe

James R Giallombardo

Khaleda Shaikh

Hans D Pinter

Peter Weuta

J&uuml;rgen Schneider

Thorsten Leidig

Daniel Czerwiec

Jurgen Dobbers

Michael Grossholz

Helmut Waldman

Michael Groβholz

Willi Potes

Karl-Ludwig Metzger

Hans-Joachim Brockhaus

Richard Malchow

Hans-Georg Janssen

Gaby Sengstock

Manfred Marre

Robert Scannel

Hans-Nicolaus Rindfleisch

Helmut H&auml;rle

Jens Camphausen

Helmut Ziegler

The invention relates to a method for recycling educt-containing process gas (residual gas) in electrochemical processes with at least one gas diffusion electrode while using a gas jet pump for directly reintroducing the residual gas in the electrochemical process.

Method of recycling process gas in electrochemical processes

An electrochemical cell comprising: (i) an anode half-cell with an anode, (ii) a cathode half-cell with a cathode, (iii) an ion-exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode comprising a gas diffusion electrode, (iv) a gap between the gas diffusion electrode and the ion-exchange membrane, (v) an electrolyte feed inlet above the gap, (vi) an electrolyte drain beneath the gap, (vii) a gas inlet, (viii) a gas outlet, and (ix) an electrolyte holding vessel comprising an overflow connected with the electrolyte feed inlet.

Electrochemical cell

The invention describes an electrochemical cell for the electrolysis of an aqueous solution of hydrogen chloride, comprising at least an anode half-cell with an anode, a cathode half-cell with a gas diffusion electrode as cathode and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the membrane consisting of at least a perfluorosulfonic acid polymer, wherein the gas diffusion electrode and the ion exchange membrane are adjacent to each other, characterised in that the gas diffusion electrode and the ion exchange membrane, under a pressure of 250 g/cmand at a temperature of 60&#xb0; C., have a contact area of at least 50%, with respect to the geometric area.

The present invention describes an electrochemical half-cell, comprising a gas space, an electrolyte space and a gas diffusion electrode in the form of a cathode or anode. The gas diffusion electrode separates the gas space from the electrolyte space and comprises an electrically conductive substrate and an electrochemically active coating. The gas diffusion electrode includes a coating-free edge region and is connected to a support structure in the coating-free edge region via an electrically conductive plate, which covers at least the coating-free edge region as well as a coated edge region.

Electrochemical half-cell

A method is described for the electrolysis of an aqueous solution of hydrogen chloride or alkali metal chloride in an electrolysis cell. The cell includes at least of an anode half-element and an anode, a cathode half-element and a gas diffusion electrode as the cathode, and a cation exchange membrane for separating the anode half-element and the cathode half-element. A gas containing oxygen is supplied to the cathode half-element and excess gas containing oxygen is discharged from the cathode half-element. Excess gas containing oxygen discharged from the cathode half-element is subjected to catalytic oxidation of hydrogen.

Method for the electrolysis of an aqueous solution of hydrogen chloride or alkali metal chloride

An electrolysis cell, suitable for the electrochemical production of chlorine from aqueous solutions of hydrogen chloride. The cell preferably comprises an anode space formed from an anode, an anode frame, and a back wall, the anode frame supporting the anode, and the anode space having an inlet and an outlet for the electrolyte, a cathode space formed from a current collector. The cell further preferably comprises a cathode frame and a back wall, the cathode frame supporting the current collector and the cathode space having an inlet and an outlet for the gas, a gas diffusion electrode arranged between anode and current collector and an cation exchange membrane arranged between anode and gas diffusion electrode, wherein the gas diffusion electrode is fixed on the current collector.

Electrolysis cell, especially for electrochemical production of chlorine

Electrode at least comprising an electroconductive support of a titanium-palladium alloy, titanium, tantalum or compounds or alloys of titanium or of tantalum, an electrochemically active coating and an interlayer between the support and the electrochemically active coating, wherein the interlayer consists of titanium carbide and/or titanium boride and is applied to the support by flame or plasma spraying. Process for producing these electrodes and their use in an electrochemical cell for producing chlorine or chromic acid.

Electrode for electrolysis in acidic media

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:

Method for electrolysis of aqueous solutions of hydrogen chloride

The invention describes an electrochemical cell for the membrane electrolysis process for electrolyzers with single-element technology. The cell consists of at least of 2 half-shells (), which surround an anolyte chamber () and a cathode chamber () with a membrane () arranged in between, and an anode () in the anolyte chamber (), with the cathode chamber () being provided with an oxygen-consuming cathode (), with a plurality of pressure-compensated gas pockets () arranged one above the other, a catholyte gap () and optionally a back chamber (), where electrically conducting supporting elements () are provided in the anolyte chamber () and supporting elements () are provided in the cathode chamber () at the same position opposite one another.

Electrochemical cell for electrolyzers with stand-alone element technology

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&#xb0; C.

Process for the electrolysis of an aqueous solution of alkali metal chloride

The invention relates to an electrolysis cell comprising an anode frame (), an anode (), a cation-exchange membrane (), a gas diffusion electrode (), a current collector () and a cathode frame (), with the anode (), the cation-exchange membrane (), the gas diffusion electrode () and the current collector () being held together elastically so that there is no gap between the individual components anode (), cation-exchange membrane (), gas diffusion electrode () and current collector (). The elastic cohesion is preferably achieved by the current collector () being elastically fastened to the cathode frame () and/or the anode () being elastically fastened to the anode frame ().

Electrolysis cell, in particular for the electrochemical preparation of chlorine

A method for producing gas diffusion electrodes, in particular for use in electrolysis cells, as well as electrodes and their uses are described. A method of the present invention involves first, a sheet-like structure is produced by means of a pair of rolls by rolling a powder mixture containing at least one catalyst or a catalyst mixture and a binder, and then the sheet-like structure is connected to an electrically conductive catalyst support by rolling by means of a pair of rolls. In one embodiment the clamping force of the rolls is preferably kept constant in the range from 0.2 kN/cm to 15 kN/cm.

Method for producing gas diffusion electrodes

The invention relates to a process for the electrochemical preparation of chlorine from aqueous solutions of hydrogen chloride in an electrolysis cell, comprising an anode chamber and a cathode chamber, the anode chamber being separated from the cathode chamber by a cation exchange membrane, the anode chamber containing an anode and the cathode chamber a gas diffusion cathode, and the aqueous solution of hydrogen chloride being passed into the anode chamber and an oxygen-containing gas into the cathode chamber, and the oxygen pressure in the cathode chamber being at least about 1.05 bar.

Process for the electrochemical preparation of chlorine from aqueous solutions of hydrogen chloride

The invention relates to an electrochemical half cell ( ) which consists of at least one membrane ( ), an electrode ( ) as anode or cathode which optionally produces gas, optionally an outlet ( ) for the gas and a support structure ( ) linking the electrode which optionally produces gas with the back wall ( ) of the half cell. The support structure ( ) divides the interior ( ) of the half cell ( ) into vertically arranged channels ( ). The electrolyte ( ) flows upwards in the electrode channels ( ) facing the electrode ( ) and flows downwards in the channels ( ) facing away from the electrode ( ). The electrode channels ( ) and the channels ( ) facing away from the electrode ( ) are interlinked at their upper and lower ends.

Membrane electrolytic cell with active gas/liquid separation

A process for electrolyzing an aqueous solution of hydrochloric acid to chlorine in an electrochemical cell provided with an anode compartment and a cathode compartment including at least one gas diffusion cathode comprising an electrically conductive web provided on at least one side thereof with a coating of a catalyst for the electroreduction of oxygen comprising rhodium sulfide and optionally containing at least one fluorinated binder incorporated therein, comprising introducing aqueous hydrochloric acid containing contaminant species into the anode compartment and oxygen into the cathode compartment while impressing a direct electric current on the cell.

Process for the electrolysis of technical-grade hydrochloric acid contaminated with organic substances using oxygen-consuming cathodes

Growing community of inventors

Leverkusen, Germany

Fritz Gestermann