Abstract: 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.

Abstract: 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.

Abstract: In the process for working up the reaction gas consisting of chlorine, hydrogen chloride, oxygen and water vapour produced in a chlorine reactor, the reaction gas leaving the reactor 1 is first cooled until the water of reaction and hydrogen chloride condense in the form of concentrated hydrochloric acid. The concentrated hydrochloric acid is then separated from the reaction gas in a phase separation column 3 and discharged. The remaining reaction gas, from which the substantial proportion of the water and a proportion of the hydrogen chloride has been removed, is then post-dried in a drying tower 6. The post-dried reaction gas consisting of chlorine, oxygen and hydrogen chloride is then compressed to 1 to 30 bar by a compressor 7. In the subsequent stage, the compressed reaction gas is passed through a cooled chlorine recuperator 8, wherein the chlorine is very largely liquefied.

Abstract: A method is described for the electrochemical processing of HCL gas to high-purity chlorine in which the process of an HCL gas-phase electrolysis with purified HCL gas from, for example, chemical reactions is coupled to a hydrochloric acid electrolysis with dilute hydrochloric acid, with the use if desired of a consumable oxygen cathode.

Abstract: This invention relates to an electrochemical half cell having a gas diffusion electrode as an anode or cathode, in which the gas space behind the gas diffusion electrode is optionally partitioned, for pressure equalization, into gas compartments which are joined to the gas diffusion electrode and which can be removed from the half cell or changed as a unit.

Abstract: The invention relates to a process for the electrolysis of sodium chloride-containing brine with parallel operation of amalgam electrolysis units (5) and membrane electrolysis units (4) with a common brine circuit using a mercury-resistant oxygen consumable cathode in the membrane electrolysis unit (4).

Abstract: The invention relates to an electrochemical half cell (1) comprising at least one electrode space (3, 15) for receiving an electrolyte (100), a gas space (2), and at least one gas diffusion electrode (14) as anode or cathode separating the gas space (2) and electrode space (3, 15), in which the gas space (2) is subdivided into two or more superimposed gas pockets (2a, 2b), in which gas inflow and gas outflow takes place through separate openings (7) and (12a, 12b, 12c, 12d) and the pressure on the electrolyte side of the electrode (14) is compensated by an opening in the respective gas pocket (2a, 2b) for the electrolyte.

Abstract: The invention relates to a pump for discharging hot corrosive liquids, in particular molten salts, consisting of a pump pipe (1), a discharge pipe (2) dipping into the liquid and at least two valves (3, 4), whereby the liquid is discharged periodically by pressurisation.

Abstract: The invention relates to an electrochemical half-cell (1) with a gas diffusion electrode (7) as cathode or anode wherein the gas chamber (6) is divided in particular into two or more gas pockets (6a, 6b, 6c) arranged one above another, the electrode chamber (2) of the half-cell (1) being divided into compartments (2a, 2b, 2c) which for the passage of the electrolyte (23), are connected to one another in cascade fashion via chutes (17), (18), (19).

Abstract: An electrochemical cell (1 ) having a proton-conducting membrane (4) is used in the process for the direct electrochemical gas phase synthesis of phosgene. Dry HCl gas and dry CO gas are supplied as the educts to the anode (2) of the electrochemical cell (1). The chlorine radicals formed on anodic oxidation of the HCl gas then react directly with the CO gas to yield phosgene, while the simultaneously formed protons migrate through the membrane (4) to the cathode (3) and are there reduced to hydrogen or, in the presence of oxygen, to water.

Abstract: In the method for the chemical reaction of gaseous educts, the educts are brought to reaction in a phase contact apparatus 1 in the presence of a catalytically active corrosive liquid. This corrosive liquid is delivered hydropneumatically in an intermittent cycle in the circuit from a sump vessel 4 connected to the lower end of the phase contact apparatus 1 to a supply vessel 9, connected to the upper end of the phase contact apparatus (delivery cycle), from which the corrosive liquid drains through the phase contact apparatus 1 and a connecting line 11 connected at its lower end and then collects in the sump vessel 4 (drainage cycle).

Abstract: The invention relates to an electrochemical half-cell consisting in at least one electrode chamber 14 for accommodation an electrolyte, a gas chamber 23 and at least one gas-diffusion electrode 5 as anode or cathode separating gas chamber 23 and electrode chamber 14, in which the gas chamber 23 is divided into two or more gas pockets 20, 20' superimposed on one another after the manner of a cascade, with which the gas supply or gas discharge takes place through openings 11, 12 to the electrolyte 22.

Abstract: In the method for the chemical reaction of gaseous educts the educts are brought to reaction in a phase contact apparatus 1 in the presence of a catalytically active corrosive liquid. This corrosive liquid is delivered hydropneumatically in an intermittent cycle in the circuit from a sump vessel 4 connected to the lower end of the phase contact apparatus 1 to a supply vessel 9, connected to the upper end of the phase contact apparatus (delivery cycle), from which the corrosive liquid drains through the phase contact apparatus 1 and a connecting line 11 connected at its lower end and then collects in the sump vessel 4 (drainage cycle).

Abstract: A pump for delivering hot, corrosive material having a shaft seal comprising a seal gap through which hot gases flow, and wherein the sealing gases also flow around the pump bearings for the purpose of cooling the bearings.