Low risk chlorine dioxide onsite generation system

1. A method of treating process water, comprising:

feeding a first solution comprising an acid through a first feed line into a mixing device;

feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;

mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is connected to a reactor;

feeding the reaction mixture into the reactor;

reacting the acid, the chlorate, and the hydrogen peroxide to produce chlorine dioxide in the reactor, wherein the reactor comprises a proximal portion connected to the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degrees to about 60 degrees;

mixing the chlorine dioxide with motive water in the motive water line at the distal portion of the reactor; and

injecting the chlorine dioxide and the motive water into the process water.

2. The method of claim 1 , further comprising cooling the mixing device and the reactor with the motive water.

3. The method of claim 1 , wherein the acid is sulfuric acid.

4. The method of claim 1 , wherein the first feed line and the second feed line are opposite to and directed against each other.

5. The method of claim 1 , wherein the motive water line comprises at least two longitudinal channels through which motive water may flow.

6. The method of claim 5 , wherein the reaction mixture has a residence time in the reactor of at least about 0.1 minute, and a precursor velocity is at least about 25 cm/min, wherein the precursor velocity is a velocity of the first and second solutions.

7. The method of claim 6 , wherein the reactor is operated at a pressure about equal to or greater than atmospheric pressure.

8. The method of claim 1 , further comprising producing the chlorine dioxide at a rate ranging from about 0.001 lb/hour to about 20 lb/hour.

9. The method of claim 1 , further comprising operating the reactor at a temperature ranging from about 2° C. to about 80° C.

10. The method of claim 1 , further comprising determining a chlorine dioxide demand in the process water using measurements selected from a chlorine dioxide sensor, an oxidation and reduction potential, a flow meter, a microbiological measurement, and any combination thereof.

11. The method of claim 1 , wherein a cooling tower comprises the process water.

12. A method, comprising:

feeding a first solution comprising an acid through a first feed line into a mixing device;

feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;

mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is connected to a reactor;

feeding the reaction mixture into the reactor;

reacting the acid, the chlorate, and the hydrogen peroxide to produce chlorine dioxide in the reactor, wherein the reactor comprises a proximal portion connected to the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degrees to about 60 degrees;

mixing the chlorine dioxide with motive water in the motive water line at the distal portion of the reactor; and

injecting the chlorine dioxide into an aqueous system.

13. The method of claim 12 , wherein the reactor is in fluid communication with a product feed line.

14. The method of claim 12 , further comprising determining a flow rate of the first solution in the first feed line.

15. The method of claim 12 , further comprising determining a flow rate of the second solution in the second feed line.

16. The method of claim 12 , further comprising determining a flow rate of a chlorine dioxide solution in a product feed line.

17. The method of claim 12 , further comprising determining a flow rate of the motive water in the motive water line.

18. The method of claim 12 , further comprising sensing a reactor pressure.

19. A method of producing chlorine dioxide, comprising:

feeding a first solution comprising an acid through a first feed line into a mixing device;

feeding a second solution comprising chlorate and hydrogen peroxide through a second feed line into the mixing device;

mixing the first solution and the second solution in the mixing device to form a reaction mixture, wherein the mixing device is in fluid communication with a reactor;

feeding the reaction mixture into the reactor;

reacting the acid, the chlorate, and the hydrogen peroxide in the reactor, wherein the reactor comprises a proximal portion in fluid communication with the mixing device and a distal portion in fluid communication with a motive water line, wherein the mixing device, the reactor, a portion of the first feed line, and a portion of the second feed line are positioned within the motive water line, wherein the reactor comprises a coiled configuration having a coil plane angle of about 1 degree to about 60 degrees; and

mixing chlorine dioxide with motive water in the motive water line at the distal portion of the reactor.

20. The method of claim 19 , wherein the acid is sulfuric acid.

21. The method of claim 19 , wherein the reactor is operated at a pressure about equal to or greater than atmospheric pressure.

22. The method of claim 19 , further comprising producing the chlorine dioxide at a rate ranging from about 0.001 lb/hour to about 20 lb/hour.

23. The method of claim 19 , further comprising operating the reactor at a temperature ranging from about 2° C. to about 80° C.