Patent ID: 6444107
Filing Date: 2002-09-03
Classification: B01D,Y02A

Abstract:
A method for a simultaneous production of acid and base of high purity by an electrodialytic splitting of a corresponding water-soluble halide-containing salt without a simultaneous formation of a halogen from halide ions of the salt with an electrodialysis cell, which comprises:providing a cathode chamber having a cathode, an inlet opening and at least one outlet opening for fluids; providing a salt chamber separated from the cathode chamber by a cationic exchanger membrane, the salt chamber having an inlet opening and an outlet opening for conducting a salt solution; forming an acid in an acid chamber separated from the salt chamber by an anionic exchanger membrane, the acid chamber not containing an anode, thereby avoiding formation of halogen by anodic oxidation of halide anions within the acid chamber; providing an anode chamber separated from the acid chamber by a cationic exchanger membrane through which protons required for forming the acid pass from the anode chamber into the acid chamber, the anode chamber having an inlet opening and an outlet opening for a liquid proton carrier flowing through the anode chamber, and the anode chamber having a hydrogen-consuming anode for converting hydrogen into protons to an extent required for forming the acid, the side of the hydrogen-consuming anode facing the anode chamber being bounded to a further cationic exchanger membrane; applying an electrical voltage between the anode and the cathode for maintaining an electrodialytic process; causing cations of a halide-containing salt to travel under the effect of the electrical field, from the salt chamber, through the cationic exchanger membrane into the cathode chamber and form a base there with OHâˆ’-ions produced by catholytic splitting of water into hydrogen and OHâˆ’-ions; and simultaneously causing anions of the halide-containing salt to travel from the salt chamber, under the effect of the electrical field, through the anionic exchanger membrane into the acid chamber and form the acid there with protons formed analytically from hydrogen at the hydrogen-consuming anode.