Process and apparatus for generating haloamine biocide
Haloamine biocides are prepared via multi-step processes in an integrated apparatus comprising an electrochemical cell and a mixing chamber, wherein active halogen donor species are electrochemically generated and subsequently reacted with amine-containing compositions to form haloamine biocide. Haloamine biocides prepared according to such processes are used to treat liquids in order to inhibit, reduce, and/or control microorganism growth therein.
1. A process for preparing haloamine biocide in an integrated apparatus comprising an undivided electrochemical cell and a mixing chamber, wherein the cell comprises an anode and a cathode located in the cell at a distance from each other sufficient to minimize degradation of an active halogen donor species, wherein a first conduit that acts as the mixing chamber is connected to the cell at point proximate the anode, and wherein a second conduit having a first and second end is connected to the cell at the first end at a point proximate the cathode and to the first conduit at the second end, the process comprising the steps of:
(a) charging the electrochemical cell with a solution comprising halide salt;
(b) electrochemically generating at least one active halogen donor species in the electrochemical cell at the anode, and electrochemically generating hydroxide in the electrochemical cell at the cathode at temperature in the range of from about 0° C. to about 25° C.;
(c) transferring a solution of the electrochemically generated hydroxide from the cathode through the second conduit to mix with a solution of the at least one active halogen donor species in the first conduit prior to mixing with an at least one amine-containing composition, where upon mixing the pH of the solution of the at least one active halogen donor species is increased; and
(d) combining the at least one active halogen donor species with the at least one amine-containing composition in the mixing chamber, wherein the combining is achieved by:
(i) transferring the at least one active halogen donor species as a stream via the first conduit after the transferring of step (c); and
(ii) merging the stream of (i) with the stream of at least one amine-containing composition; wherein at least a portion of the at least one active halogen donor species reacts with at least a portion of the at least one amine-containing composition to form haloamine biocide and wherein a yield of a resulting monohaloamine is at least 80% provided that the at least one active halogen donor species comprises hypochlorite, hypochlorous acid, hypobromite, hypobromous acid or any combination thereof.
2. The process of claim 1 wherein the at least one amine-containing composition comprises at least one ammonium salt.
3. The process of claim 1 wherein the at least one amine-containing composition is selected from the group consisting of ammonia, ammonium hydroxide, ammonium sulfate, ammonium carbonate, ammonium phosphate, ammonium nitrate, ammonium halide, or combinations thereof.
4. The process of claim 1 wherein the at least one amine-containing composition is selected from the group consisting of hydrazine, hydroxylamine, alkyl hydrazine, alkyl hydroxylamine, aryl hydrazine, aryl hydroxylamine, or combinations thereof.
5. The process of claim 1 wherein the at least one amine-containing composition comprises at least one organic amine.
6. The process of claim 5 wherein the at least one organic amine is selected from the group consisting of dialkylhydantoin, cyanuric acid, isocyanuric acid, ethylene diamine, ethanolamine, diethylene triamine, piperidine, glucosamine, acetamide, formamide, methanesulfonamide, urea, succinimide, taurine, sulfamic acid, β-alanine, glucuronamide, amino acids, and combinations thereof.
7. The process of claim 1 wherein the at least one amine-containing composition comprises at least one polymeric amine.
8. The process of claim 1 wherein the at least one amine-containing composition comprises an inorganic amine source and wherein the at least one active halogen donor species and the at least one amine-containing composition are each present in a concentration of about 0.01 to 1.0% by weight.
9. The process of claim 1 wherein the at least one amine-containing composition comprises an inorganic amine source and the pH is in the range from about 9.0 to about 11.0.