Electrolytic process for producing chlorine dioxide
AssigneeSterling Pulp Chemicals, Ltd.
InventorsMarek Lipsztajn, Gerald Cowley, Jerry J. Kaczur
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Abstract
A process for converting in a single pass an aqueous alkaline pH, alkali metal chlorite solution into an aqueous chlorine dioxide-containing solution that involves the combination of (1) using an electrochemical acidification cell to lower the pH value of the aqueous alkali metal chlorite feed before it enters the anode compartment of an electrochemical oxidation cell where the chlorite is converted to chlorine dioxide with (2) using an anolyte flow pattern where the anolyte passes through a porous, high surface area electrode. This process results in a substantially improved conversion efficiency per pass.
Claims23
A process for converting an aqueous alkaline pH alkali metal chlorite solution into an aqueous chlorine dioxide-containing solution in a single pass by:
- (1) acidifying an aqueous alkaline pH alkali metal chlorite solution to produce an aqueous acidified alkali metal chlorite solution having a pH less than 7;
- and then
- (2) passing the acidified aqueous alkali metal chlorite solution through a porous, high surface area electrode in the anode compartment of an electrochemical oxidation cell to convert at least a portion of said alkali metal chlorite to chlorine dioxide, and to produce an aqueous chlorine dioxide-containing solution.
A process for converting an alkaline pH alkali metal chlorite solution into an aqueous chlorine dioxide-containing solution in a single pass by:
- (1) acidifying an alkaline pH alkali metal chlorite solution by passing said aqueous alkaline pH alkali metal chlorite solution through an electrochemical acidification cell having a low surface area anode to produce an aqueous acidified alkali metal chlorite solution having a pH less than 7, and then
- (2) passing the acidified aqueous alkali metal chlorite solution through a porous, high surface area electrode in the anode compartment of an electrochemical oxidation cell to convert at least a portion of said alkali metal chlorite to chlorine dioxide, and to produce an aqueous chlorine dioxide-containing solution.
Dependencies are inferred from the claim text.