Method for producing chlorous acid aqueous solution by adsorption of chlorine dioxide

Abstract

The present invention addresses the problem of providing a novel technique for producing aqueous chlorous acid. The present invention provides a method for producing chlorous acid, which comprises a step of adding chlorine dioxide (ClO 2 ) to one or more components independently selected from an inorganic acid, an inorganic acid salt, an organic acid and an organic acid salt or a combination of two or more of the aforementioned components. In the method, chlorine dioxide (ClO 2 ) is provided in the form of a gas. The method also comprises, subsequent to the above-mentioned addition step, a step of further adding one or more components independently selected from an inorganic acid, an inorganic acid salt, an organic acid and an organic acid salt or a combination of two or more of the aforementioned components.

1 . A method of manufacturing a chlorous acid aqueous solution, comprising the step of:
 trapping chlorine dioxide (ClO 2 ) with aqueous solution A comprising one of an inorganic acid, inorganic acid salt, organic acid, and organic acid salt, two or more types thereof or a combination thereof.   
     
     
         2 . The method of  claim 1 , further comprising the step of adding the chlorine dioxide in the presence of hydrogen peroxide. 
     
     
         3 . The method of  claim 1 , wherein a pH of the aqueous solution A is 11.0 or less and 6.0 or greater. 
     
     
         4 . The method of  claim 1 , wherein a pH of the aqueous solution A is 10.8 or less and 10.2 or greater. 
     
     
         5 . The method of  claim 1 , wherein the chlorine dioxide (ClO 2 ) is provided as gas. 
     
     
         6 . The method of  claim 1 , comprising, after the step of adding, a step of further adding aqueous solution B comprising one of an inorganic acid, inorganic acid salt, organic acid, and organic acid salt, two or more types thereof or a combination thereof. 
     
     
         7 . The method of  claim 1 , wherein the inorganic acid is carbonic acid, phosphoric acid, boric acid, or sulfuric acid; and the inorganic acid salt is carbonate, hydroxide, phosphate, or borate. 
     
     
         8 . The method of  claim 7 , wherein the carbonate is sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate, and the hydroxide is sodium hydroxide, potassium hydroxide, calcium hydroxide, or barium hydroxide. 
     
     
         9 . The method of  claim 7 , wherein the phosphate is disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate. 
     
     
         10 . The method of  claim 7 , wherein the borate is sodium borate or potassium borate. 
     
     
         11 . The method of  claim 1 , wherein the organic acid salt is succinic acid, citric acid, malic acid, acetic acid, or lactic acid. 
     
     
         12 . The method of  claim 1 , wherein the organic acid salt is sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate. 
     
     
         13 . The method of  claim 1 , wherein TAL of the aqueous solution A is 20 to 2000, wherein the TAL is found by an amount of 0.1N—HCl titration from an initial pH at or below pH of 11.0 to a pH of 
     
     
         14 . The method of  claim 6 , wherein a pH of a liquid after adding the aqueous solution B is 3.2 or greater and less than 7.0, or a pH of a liquid after adding the aqueous solution B is 4.0 or greater and less than 7.0, or a pH of a liquid after adding the aqueous solution B is about 5.0 or greater and less than 7.0. 
     
     
         15 . The method of  claim 1 , wherein the chlorine dioxide is present at a concentration of 0.8 to 1.0%. 
     
     
         16 . A chlorous acid aqueous solution manufactured by a method comprising the step of trapping chlorine dioxide (ClO 2 ) with aqueous solution A comprising one of an inorganic acid, inorganic acid salt, organic acid, and organic acid salt, two or more types thereof or a combination thereof. 
     
     
         17 . The chlorous acid aqueous solution of  claim 16 , wherein the method further comprises a step of adding the chlorine dioxide in the presence of hydrogen peroxide. 
     
     
         18 . The chlorous acid aqueous solution of  claim 16 , wherein a pH of the aqueous solution A is 11.0 or less and 6.0 or greater. 
     
     
         19 . The chlorous acid aqueous solution of  claim 16 , wherein a pH of the aqueous solution A is 10.8 or less and 10.2 or greater. 
     
     
         20 . The chlorous acid aqueous solution of  claim 16 , wherein the chlorine dioxide (ClO 2 ) is provided as gas. <PCT claim  24 >