ELECTROLYTIC DEVICE FOR GENERATION OF pH-CONTROLLED HYPOHALOUS ACID AQUEOUS SOLUTIONS FOR DISINFECTANT APPLICATIONS

Abstract

An electrolytic device for the generation of hypohalous acid in aqueous solutions includes at least a single liquid chamber for receiving an aqueous solution containing halide ions therein, the single liquid chamber having an exterior wall and a solid anode contained within to provide for the oxidation of the halide ions, which, in turn, provides for the formation of hypohalous acid in aqueous solution, and a gas permeable cathode forming a portion of the exterior wall of the single liquid chamber, the cathode providing for the reduction of oxygen to provide hydroxyl ions in solution within the single liquid chamber to mix with the products generated at the anode. An embodiment of the electrolytic device including an anolyte chamber and a catholyte chamber separated by an ionomeric membrane is also described, whereby the anolyte chamber further includes an outlet including a pH control for determining and regulating the pH of the exiting anolyte effluent to between about 4 and 9. The product is suitable for disinfectant applications including as a hand sanitizer.

1 . An electrolytic device for the generation of hypohalous acid in aqueous solutions, the device comprising:
 a single liquid chamber having an inlet for receiving an aqueous solution containing halide ions therein, the single liquid chamber having an exterior wall and a solid anode contained within the single liquid chamber providing for the oxidation of the halide ions to provide an aqueous solution of hypohalous acid; and   a gas permeable cathode forming at least a portion of the exterior wall of the single liquid chamber, the cathode providing for the reduction of oxygen to provide hydroxyl ions in solution within the single liquid chamber to mix with the hypohalous acid produced at the anode, the cathode having a hydrophobic surface for receiving oxygen from outside the single liquid chamber and a hydrophilic surface in contact with the electrolyte solution allowing for reduction of dioxygen.   
     
     
         2 . The electrolytic device as claimed in  claim 1 , wherein the single liquid chamber further includes an outlet including a pH control device for determining the pH of the exiting mixed effluent. 
     
     
         3 . The electrolytic device as claimed in  claim 1 , wherein the hypohalous acid is hypochlorous acid and the halide ions are chloride ions. 
     
     
         4 . The electrolytic device as claimed in  claim 1 , further including a gas compartment for providing oxygen to the gas permeable cathode, wherein the gas compartment is defined by at least one exterior wall that encloses the portion of the exterior wall of the single liquid chamber composed of the gas permeable cathode within the gas compartment. 
     
     
         5 . The electrolytic device as claimed in  claim 4 , wherein the gas compartment includes an inlet for receiving oxygen into the gas compartment. 
     
     
         6 . The electrolytic device as claimed in  claim 1 , wherein the solid anode is a dimensionally stable anode. 
     
     
         7 . The electrolytic device as claimed in  claim 1 , wherein the gas permeable cathode is a gas diffusion electrode. 
     
     
         8 . The electrolytic device as claimed in  claim 2 , wherein the pH control for determining the pH is a pH meter and sensor. 
     
     
         9 . An electrolytic device for the generation of hypohalous acid in aqueous solutions, the device comprising:
 an anolyte chamber having an inlet for receiving an aqueous solution containing halide ions therein, the anolyte chamber having an exterior wall and a solid anode contained within the anolyte chamber providing for the oxidation of the halide ions to provide an anolyte effluent of hypohalous acid in aqueous solution;   a catholyte chamber having an inlet for receiving an aqueous electrolyte, wherein the catholyte chamber is defined by at least one exterior wall or portion thereof comprising a gas permeable cathode, the cathode having a hydrophobic surface for receiving oxygen from outside the catholyte chamber and a hydrophilic surface allowing for reduction of dioxygen; and   an ionomeric membrane for partitioning the anolyte chamber from the catholyte chamber;   wherein the anolyte chamber further includes an outlet including a pH control for determining and regulating the pH of the exiting anolyte effluent to between about 4 and 9.   
     
     
         10 . The electrolytic device as claimed in  claim 9 , wherein the catholyte chamber includes reacted catholyte effluent therein. 
     
     
         11 . The electrolytic device as claimed in  claim 10 , wherein catholyte chamber includes an outlet for releasing any reacted catholyte effluent remaining in the catholyte chamber to mix with the exiting anolyte effluent. 
     
     
         12 . The electrolytic device as claimed in  claim 11 , wherein the pH control for regulating the pH includes a valve and a recirculator for recirculating the flow of the exiting mixed anolyte and catholyte effluents back into the anolyte chamber when the mixed anolyte and catholyte effluents have a pH that is greater than 9. 
     
     
         13 . The electrolytic device as claimed in  claim 9 , further including an inlet valve for releasing a buffering agent into the anolyte chamber of aqueous solution containing halide ions. 
     
     
         14 . The electrolytic device as claimed in  claim 9 , wherein the pH of the mixed anolyte and catholyte effluents is regulated between about 5 and 8. 
     
     
         15 . A method for the generation of hypohalous acid comprising:
 oxidizing halide ions in the presence of water within a single liquid chamber to form an aqueous solution of hypohalous acid;   feeding oxygen through a gas permeable cathode to reduce the oxygen in the presence of water to form hydroxyl ions, wherein the gas permeable cathode forms at least a portion of an exterior wall of the single liquid chamber;   mixing the solution containing hydroxyl ions in an amount sufficient to complete the electrical circuit within the device and to produce hypohalous acid;   determining the pH of the hypohalous acid to ensure that the pH is between about 4 and 9; and   removing the hypohalous acid.   
     
     
         16 . The method of  claim 15 , wherein the step of determining the pH of the hypohalous acid includes the use of a pH meter. 
     
     
         17 . The method of  claim 15 , wherein the step of feeding oxygen to the gas permeable cathode includes delivering oxygen from a gas compartment, wherein the portion of the exterior wall of the single liquid chamber comprised of the gas permeable cathode is included in the gas compartment. 
     
     
         18 . A method for the generation of hypohalous acid comprising:
 oxidizing halide ions in the presence of water within an anolyte chamber to form an anolyte effluent containing hypohalous acid;   feeding oxygen through a gas permeable cathode to reduce the oxygen in the presence of water to form a catholyte effluent containing hydroxyl ions, wherein the gas permeable cathode forms at least a portion of an exterior wall of a catholyte chamber;   mixing the solution containing the hydroxyl ions in an amount sufficient to complete the electrical circuit within the device to produce hypohalous acid;   controlling the pH of the hypohalous acid to ensure that the pH is between about 4 and 9; and   removing the hypohalous acid.   
     
     
         19 . The method of  claim 18 , wherein the step of controlling the pH of the hypohalous acid further includes the steps of determining the pH of the hypohalous acid and regulating the pH of the hypohalous acid. 
     
     
         20 . The method of  claim 19 , wherein the step of determining the pH of the hypohalous acid includes the use of a pH meter and sensor. 
     
     
         21 . The method of  claim 19 , wherein the step of regulating the pH of the hypohalous acid further includes mixing the exiting anolyte and catholyte effluents in an amount sufficient to increase the pH of the hypohalous acid to ensure that the pH is between about 4 and 9. 
     
     
         22 . The method of  claim 21 , further comprising the step of determining the pH of the hypohalous acid after mixing the exiting anolyte and catholyte effluents, wherein the step includes the use of a pH meter. 
     
     
         23 . The method of  claim 21 , wherein the step of regulating the pH of the hypohalous acid further includes recirculating the flow of the hypohalous acid back to the anolyte chamber if the pH of the hypohalous acid is below 4 or above 9. 
     
     
         24 . The method of  claim 23 , further comprising the step of determining the pH of the hypohalous acid after recirculating the flow of the hypohalous acid back to the anolyte chamber, wherein the step includes the use of a pH meter and sensor. 
     
     
         25 . The method of  claim 18 , wherein the step of feeding oxygen to the gas permeable cathode includes delivering oxygen from a gas compartment, wherein the portion of the exterior wall of the catholyte chamber comprised of the gas permeable cathode is included in the gas compartment.