Granted Patent B2

US 10,472,237 · App. 15/735,230 · Granted Nov 12, 2019

Abstract

Claims (27)

1. An aqueous composition for producing chlorine dioxide upon contact with an acid, the composition comprising:

a chlorite ion source comprising a chlorite; and

water,

wherein the pH of the aqueous composition is at least 11.5, the composition produces chlorine dioxide upon contact with an acid, and the molar ratio of the chlorite to the thiosulfate in the composition is from 20:1 to 2:1.

2. The composition according to claim 1 , further comprising a separate source of alkalinity.

3. The composition according to claim 2 , wherein the separate source of alkalinity comprises at least one selected from the group consisting of hydroxides, carbonates, silicates, and amines.

4. The composition according to claim 1 , wherein the composition produces chlorine dioxide at a concentration of 0.01 to 100 ppm when the composition contacts the acid.

5. The composition according to claim 1 , wherein the molar ratio of the chlorite to the thiosulfate in the composition is from 20:1 to 4:1.

6. The composition according to claim 1 , wherein the chlorite is selected from sodium chlorite and calcium chlorite and the thiosulfate is selected from sodium thiosulfate and potassium thiosulfate.

7. The composition according to claim 1 , wherein the chlorite is sodium chlorite and the thiosulfate is sodium thiosulfate.

8. The composition according to claim 1 , consisting of the thiosulfate, the chlorite, the water, a separate source of alkalinity, and optionally, a corrosion inhibitor selected from aminotris(methylenephosphonic acid) (ATMP), 1-hydroxyethane 1,1-diphosphonic acid (HEDP), and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC).

9. A clean-in-place system comprising a tank comprising the composition according to claim 1 and a separate source of the acid.

10. An aqueous composition for producing chlorine dioxide upon contact with an acid, the composition comprising:

a chlorite ion source comprising a chlorite; and

water,

wherein the pH of the aqueous composition is at least 10.39, the composition produces chlorine dioxide upon contact with an acid, and the molar ratio of the chlorite to the iodide in the composition is from 40:1 to 1:1.

11. The composition according to claim 10 , wherein the molar ratio of the chlorite to the iodide in the composition is from 40:1 to 2:1.

12. The composition according to claim 10 , wherein the chlorite is selected from sodium chlorite and calcium chlorite and the iodide is selected from sodium iodide and potassium iodide.

13. The composition according to claim 10 , wherein the chlorite is sodium chlorite and the iodide is potassium thiosulfate.

14. The composition according to claim 10 , consisting of the iodide, the chlorite, the water, a separate source of alkalinity, and optionally, a corrosion inhibitor selected from aminotris(methylenephosphonic acid) (ATMP), 1-hydroxyethane 1,1-diphosphonic acid (HEDP), and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC).

15. A clean-in-place system comprising a tank comprising the composition according to claim 10 and a separate source of the acid.

16. A method of producing chlorine dioxide comprising:

contacting the aqueous composition according to claim 1 with the acid.

17. The method according to claim 16 , further comprising applying chlorine dioxide, produced by contacting the aqueous composition with the acid, in at least one process selected from the group consisting of a disinfection process, a sanitization process, a cleaning process, and a sterilization process.

18. The method according to claim 16 , wherein the acid comprises at least one selected from the group consisting of an acidic biocide, an acidic detergent, an acidic descaler, an acidic sanitizer, and an acidic disinfectant.

19. The method according to claim 16 , wherein the acid is in the form of an acidic foam.

20. The method according to claim 16 , wherein a concentration of the chlorine dioxide produced is 0.01 to 100 ppm.

Assignments (13)