Electrolytic production of halogen based disinfectant solutions from halide containing waters and uses thereof

Patent metadata

Field	Value
Publication number	US-2018282882-A1
Application number	US-201615765765-A
Country	US
Kind code	A1
Filing date	Oct 6, 2016
Priority date	Oct 6, 2015
Publication date	Oct 4, 2018
Grant date	—

Abstract

Disclosed in the present invention are methods and apparatuses for the electrochemical conversion of halide ion containing brines into halogen based disinfection solutions while the impact of scale formation on electrochemical system operations. This is accomplished by controllably modifying the brine with one or more of halide ions, a halogen stabilization compound, an acid component, or a buffering component. These chemical modifications of the brine allow for the production of stabilized 10 halogen solutions, which can then be used as disinfectants. The present invention is especially useful in the production of halogen-based biocides from flowback or produced waters resulting from oil and gas production, but can be applied to any halide ion containing water stream, including reject water from reverse osmosis filtration processes or ocean water, that contains ammonia.

First claim

1 . A method for producing a microbiocidally active solution, the method comprising:
adding a halogen stabilizing compound to a brine containing ammonia or an ammonium ion containing compound; and electrolyzing the brine in an electrolytic cell, thereby producing a microbiocidally active solution comprising a stabilized halogen compound but that does not comprise trichloramine in a concentration above an odor detection threshold.

2 . The method of claim 1 wherein the microbiocidally active solution does not comprise dichloramine in a concentration above an odor detection threshold.

3 . The method of claim 1 wherein the adding step comprises adding a sufficient amount of the halogen stabilizing compound to the brine relative to the ammonia or ammonium ion containing compound to suppress formation of trichloramine and dichloramine.

4 . The method of claim 1 wherein the halogen stabilizing compound is selected from the group consisting of sulfamic acid, hydantoin, derivatives of hydantoin, succinimide, derivatives of succinimide, cyanuric acid, and organic amine compounds.

5 . The method of claim 1 wherein the stabilized halogen compound is selected from the group consisting of N-chlorosulfamic acid and N,N-dichlorosulfamic acid.

6 . The method of claim 1 further comprising adding halides to the brine to increase the halide concentration prior to the electrolyzing step.

7 . The method of claim 1 further comprising adding a buffering agent to the brine.

8 . The method of claim 7 wherein the buffering agent is selected from the group consisting of monobasic lithium phosphate (LiH 2 PO 4 ), monobasic sodium phosphate (NaH 2 PO 4 ), monobasic potassium phosphate (KH 2 PO 4 ), dibasic lithium phosphate (Li 2 HPO 4 ), dibasic sodium phosphate (Na 2 HPO 4 ), dibasic potassium phosphate (K 2 HPO 4 ), tribasic lithium phosphate (Li 3 PO 4 ), tribasic sodium phosphate (Na 3 PO 4 ), tribasic potassium phosphate (K 3 PO 4 ), and combinations thereof.

9 . The method of claim 1 comprising adding a sufficient amount of acid to the brine so that a pH of the brine prior to the electrolyzing step is less than 7.

10 . The method of claim 9 wherein the pH of the brine prior to the electrolyzing step is less than 5.

11 . The method of claim 9 wherein the pH of the brine prior to the electrolyzing step is less than 3.

12 . The method of claim 9 wherein the acid comprises the halogen stabilizing compound.

13 . The method of claim 9 wherein a pH of the microbiocidally active solution is less than 7.

14 . The method of claim 13 wherein the pH of the microbiocidally active solution is less than 3.

15 . The method of claim 9 wherein the adding step comprises adding a sufficient amount of the halogen stabilizing compound to the brine relative to amount of halide ions present in the brine such that the total halogen in the microbiocidally active solution comprises no more than approximately 20% free halogen.

16 . The method of claim 15 wherein the halogen comprises chlorine and the method further comprises minimizing the formation of chlorine gas produced during the electrolyzing step.

17 . The method of claim 9 further comprising removing and/or preventing the formation of scale in downstream components.

18 . The method of claim 17 comprising:
de-energizing the electrolytic cell, thereby stopping the electrolyzing step; and
flowing brine through the de-energized electrolytic cell to the downstream components.

19 . The method of claim 9 further comprising periodically reversing polarities of electrodes in the electrolytic cell.

20 . The method of claim 1 wherein a pH of the brine is between 6 and 8 and a pH of the microbiocidally active solution is greater than 10.

21 . The method of claim 20 wherein the pH of the microbiocidally active solution is greater than 11.

22 . The method of claim 20 wherein the microbiocidally active solution comprises monochloramine.

23 . The method of claim 20 wherein a microbial inactivation efficacy of the microbiocidally active solution is 10-100 times greater than a microbial inactivation efficacy of a solution produced by electrolyzing the brine comprising the same amount of the halogen stabilizing compound but not comprising any ammonia or ammonium ion containing compound.

Assignees

• Johnson Matthey Plc

Inventors

• Boal Andrew Kiskadden
• Sanchez Justin
• Santillanes Matthew Ronald

Classifications

• C25B15/02

  Process control or regulation · CPC title

• A01N59/00

  Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds · CPC title

• C25B1/26 Primary

  Chlorine; Compounds thereof (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34) · CPC title

• C25B15/023

  Measuring, analysing or testing during electrolytic production · CPC title

• C25B15/031

  pH · CPC title