Controlled production of halogen aqueous solutions with different compositions

Abstract

Methods and systems for the controlled production of aqueous halogen solutions with different compositions are disclosed. According to an embodiment, an aqueous solution of hypochlorite ions is modified by sequentially adding a pH-adjusting chemical, a non-chloride halide ion, and a halogen stabilizing compound. Sensors for measuring the physical and chemical properties of the solution that change due to the effects of various chemical reactions are connected to a control system, which in turn can control the input of one or more chemicals. The control system facilitates the production of a solution having desired characteristics in terms of pH, specific halogen composition, and halogen stability, and limits the production of undesired by-products, such as bromate ions.

Description

Technical Field

[0001] The present invention relates to the production of aqueous halide solutions in a controlled manner. In particular, the present invention relates to the production of aqueous solutions having different compositions of at least two aqueous halogen species in a controlled manner. Background Art

[0002] Halogen aqueous solutions are used as microbicides in many water treatment processes, such as disinfection of drinking water, wastewater, industrial cooling tower water, irrigation water, and water for oil and gas production operations. In these applications, aqueous solutions of hypochlorite ions are the most commonly used, although other aqueous halogen substances (e.g., stable bromine solutions) are also often used. Aqueous solutions with two or more aqueous halogen components are ideal because they can have many benefits in water treatment processes, including improved, complementary, or synergistic microbial killing performance or may have secondary benefits such as reduced corrosiveness and increased halogen stability. Summary of the invention

[0003] One or more embodiments of the present invention relate to methods and systems for the controlled production of halogen aqueous solutions having at least two aqueous halogen species. According to an embodiment, a system for controlling the production of halogen aqueous solutions having at least two aqueous halogen species is provided. The system includes one or more components configured to provide: an initial hypochlorite solution, a chemical substance for controlling the pH of the initial hypochlorite solution, at least one additional halogen ion, and, if necessary, at least one halogen stabilizing compound. The system also includes a control system having a plurality of sensors capable of monitoring the chemical and physical properties of the aqueous solution, a computerized control system, and various pumping mechanisms weakened by the computerized control system. The system also includes a control system for optimizing the production of a desired solution consisting of at least two aqueous halogen species while minimizing or eliminating the production of unwanted chemicals.

[0004] According to another embodiment, a method for controlling the production of an aqueous halogen solution having at least two aqueous halogen species is provided. The method includes modifying an aqueous solution of hypochlorite ions by sequentially adding a pH adjusting chemical substance, a halogen ion, and a halogen stabilizing compound. Sensors for measuring the physical and chemical properties of the solution that are changed due to the influence of various chemical reactions are connected to a control system, which in turn can control the input of one or more chemical substances. The control system promotes the production of a solution having desired characteristics in terms of pH, specific halogen composition, halogen stability, and limits the generation of undesirable byproducts (e.g., bromate ions).

[0005] According to an embodiment, a system for producing a mixed halogen aqueous solution having at least two different halogen substances comprises: (i) a first storage tank containing a chlorine-free halogen aqueous solution; (ii) one or more mixing tanks comprising a flow-blocking structure, wherein the first mixing tank is located downstream of the first storage tank; and (iii) a pipeline for conveying a flow of an aqueous hypochlorite solution to the first mixing tank. The flow-blocking structure may include one or more baffles. The halogen aqueous solution is a bromine-containing fluid. Alternatively, the halogen aqueous solution includes bromine and iodine. The system may further include a second storage tank for accommodating an aqueous hypochlorite solution. The pipeline is configured to convey the aqueous hypochlorite solution from the second storage tank to the first mixing tank. The second storage tank is located upstream of the first mixing tank.

[0006] In another embodiment, the system has an in-situ device for producing an aqueous hypochlorite solution. The device may include a conventional electrolytic cell. A pipeline is configured to transport the aqueous hypochlorite solution from the device. The device is located upstream of the first mixing tank.

[0007] The system may further include an optional third tank containing a pH adjusting chemical.

[0008] The static mixer is configured to mix the aqueous hypochlorite solution with the pH adjusting chemical before the aqueous hypochlorite solution is piped to the first mixing tank.

[0009] The system may include a first sensor group. The first sensor group is fluidly connected to the static mixer. The first sensor group includes one or more sensors for measuring at least the pH of the hypochlorite aqueous solution or the pH of the pH-adjusted hypochlorite aqueous solution before the hypochlorite aqueous solution is piped to the first mixing tank.

[0010] In the first mixing tank, the baffle is configured to promote thorough mixing of (a) the hypochlorite aqueous solution or the pH-adjusted hypochlorite aqueous solution and (b) the chlorine-free halogen aqueous solution to produce a mixed halogen aqueous solution having at least two different halogen species.

[0011] The system also includes a second sensor group located downstream of the first mixing tank. The second sensor group includes one or more sensors to measure one or more parameters of the mixed halogen aqueous solution. These parameters can be selected from the group consisting of pH, oxidation-reduction potential (ORP), UV-Vis absorption curve and combinations thereof.

[0012] The system also includes a fourth tank. The fourth tank is fluidly connected to the second sensor group. The fourth tank is configured to contain a halogen-stabilizing compound.

[0013] Pipe delivery refers to conveying the mixed halogen aqueous solution and the halogen stabilizing compound to a second mixing tank. The second mixing tank includes one or more baffles. The baffles are configured to promote thorough mixing of (a) the mixed halogen aqueous solution and (b) the halogen stabilizing compound to produce a stable mixed halogen aqueous solution having at least two different halogen species.

[0014] The fifth storage tank is located downstream of the second mixing tank. The stable mixed halogen aqueous solution is delivered to the fifth storage tank.

[0015] According to another embodiment, a method for producing a mixed halogen aqueous solution having at least two different halogen species includes: pumping a stream of an aqueous hypochlorite solution to a first mixing tank; pumping an aqueous halogen solution to the first mixing tank, wherein the aqueous halogen solution is free of chlorine; and promoting thorough mixing of the aqueous hypochlorite solution and the chlorine-free halogen aqueous solution in the first mixing tank to produce a mixed halogen aqueous solution having at least two different halogen species.

[0016] The method further comprises: (i) measuring at least the pH of the aqueous hypochlorite solution before the aqueous hypochlorite solution is delivered to the first mixing tank; and (ii) measuring one or more parameters of the mixed aqueous halogen solution, wherein the parameters are selected from the group consisting of pH, oxidation-reduction potential (ORP), UV-Vis absorption curve, and combinations thereof.

[0017] The measured value is processed to control the flow rate of the aqueous hypochlorite solution to the first mixing tank. The measured value can also be used to control the pumping rate of the aqueous hypochlorite solution and / or the aqueous halogen solution to control the reaction between the hypochlorite ions and the non-chlorine halide ions in the first mixing tank.

[0018] The objects, advantages, novel features and further scope of application of the present invention will be partially described in the following detailed description in conjunction with the accompanying drawings, and some will become obvious to those skilled in the art after studying the following content or can be learned through practice of the present invention. The objects and advantages of the present invention can be realized and obtained by the means and combinations particularly pointed out in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate several embodiments of the present invention and, together with the description, are used to explain the principles of the present invention. The accompanying drawings are only for illustrating preferred embodiments of the present invention and should not be construed as limiting the present invention. In the drawings:

[0020] Figure 1 An embodiment of a system for producing a mixed halogen aqueous solution is shown.

[0021] Figure 2 An embodiment of a system for producing a stable mixed halogen aqueous solution is shown.

[0022] Figure 3 An embodiment of a system for producing a mixed halogen aqueous solution using sodium hypochlorite produced by an electrolysis system as an initial halogen source is shown.

[0023] Figure 4 An embodiment of a system for producing a stable mixed halogen aqueous solution using sodium hypochlorite produced by an electrolysis system as an initial halogen source is shown.

[0024] Figure 5 An embodiment of a UV sensor system is shown.

[0025] Figure 6 An embodiment of a system for producing a stable mixed halogen aqueous solution is shown that uses an electrolysis process to electrolyze a pH adjusted mixed halide brine to produce a mixture of aqueous free halogens that is then reacted with a halogen stabilizing compound.

[0026] Figure 7 is a graph showing the UV-visible absorption spectrum of the halogen aqueous solution prepared as described in Example 2. DETAILED DESCRIPTION

[0027] Embodiments of the present invention and the practice of the present invention are directed to producing an aqueous solution having at least two or more different aqueous halogen species, with any desired ratio between the two or more aqueous halogen species. Within the scope of the present invention, the term "aqueous halogen species" includes dissolved halogens (molecular chlorine, molecular bromine and molecular iodine), hypohalous acids (hypochlorous acid, hypobromous acid and hypoiodous acid), hypohalite ions (hypochlorite, hypobromite and hypoiodite) and halamine species (any chemical compound having at least one nitrogen atom, wherein the nitrogen atom contains at least one chemical bond connected to at least one halogen atom).

[0028] The oxidation of bromide and iodide ions by hypochlorite ions is well known in the art and proceeds according to the following equation:

[0029] C1O - +Br - →BrO - +Cl -

[0030] C1O - +I - →IO - +Cl -

[0031] As shown above, hypochlorite ion (ClO - )Oxidation of bromide ion (Br - ) produces hypobromite ion (BrO- ), or oxidize iodide ions (I - ) produces hypoiodite ion (IO - ), in both cases, the hypochlorite ions are reduced to chloride ions (Cl - ).

[0032] In fact, aqueous halogens, especially aqueous bromine and iodine, are stabilized by combining aqueous halogens with halogen-stabilizing compounds. As used herein, the term "halogen-stabilizing compound" includes organic or inorganic amine compounds containing at least one nitrogen atom and including at least one nitrogen-hydrogen bond. When the aqueous halogen and the halogen-stabilizing compound are combined, the aqueous halogen reacts with the halogen-stabilizing compound to convert the nitrogen-hydrogen bond into a nitrogen-halogen bond, effectively producing an N-halamine compound. The halogen-stabilizing compound may include, but is not limited to, sulfamic acid, sulfamic acid salts, hydantoin, 5,5-dimethylhydantoin, taurine, and cyanuric acid.

[0033] In the practice of the present invention, the reaction between the initial hypochlorite ion, the additional halogen ions, and the halogen-stabilizing compound has been shown to affect the physical and chemical properties of the solution, such as changes in solution pH, oxidation-reduction potential (ORP), and the absorption curve of the solution in the ultraviolet and visible wavelength range (here, the wavelength range is between 200 and 800 nm) (UV-Vis absorption spectrum). According to one or more embodiments, these changes can be measured (e.g., using sensors) to provide a mechanism for controlling the entire process and the solution produced by the process. This is useful for optimizing the utilization of all chemicals used in the process and avoiding any undesirable chemicals (e.g., bromate ions (BrO 3 - ))'s unnecessary production is ideal.

[0034] Figure 1 A schematic diagram of a system 100 for controlled production of a mixed halogen aqueous solution is shown. Fresh water is piped to the system 100 via a pipeline 2. As used herein, the term "pipeline" refers to a pipe or pipeline used to transport fluids and solutions. Tank 4 contains an aqueous hypochlorite solution, which is injected into pipeline 2 by the action of a pump 6. Preferably, the aqueous hypochlorite solution contained in tank 4 is electrochemically generated, and the concentration of hypochlorite ions in the dilution stream is about 3,000 mg / L or less. In one embodiment, the aqueous hypochlorite solution contained in tank 4 may include sodium hypochlorite. However, it should be understood that any solution that primarily contains at least one hypochlorite-containing compound may be used herein.

[0035] In one embodiment, the pH of the solution can be adjusted at this stage. For example, tank 8 can contain a solution having at least one pH adjusting chemical dissolved in water, which can be combined with the hypochlorite aqueous solution in pipe 2 through the action of pump 10. According to an embodiment, the solution contained in tank 8 can include sodium hydroxide dissolved in water. However, it should be understood that any pH adjusting chemical capable of adjusting the pH of the solution containing hypochlorite ions to a desired pH can be used. In one or more embodiments, the pH adjusting chemical can adjust the pH of the hypochlorite solution to between 10-12. In another embodiment, the pH of the hypochlorite solution can be adjusted to between 10.5-11.5.

[0036] The resulting diluted hypochlorite solution then passes through a static mixer 12 where it is thoroughly mixed. It is then piped through a first sensor group 14. According to an embodiment, the sensor group 14 is configured to measure at least the pH of the diluted hypochlorite solution. However, it should be understood that the sensor group 14 can be configured to measure other solution parameters.

[0037] Tank 16 contains an aqueous halide solution having at least one halide ion. The aqueous halide solution is injected into pipe 2 by the action of pump 18. According to an embodiment, the aqueous halide solution contained in tank 16 can be sodium bromide or sodium iodide dissolved in water. However, it should be understood that a combination of these two compounds or any solution containing at least one compound having at least a bromide or iodide ion component can be used, including but not limited to quaternary ammonium bromide and quaternary ammonium iodide compounds.

[0038] The combined halogen solution can be piped to the mixing tank 20. In one or more embodiments, the mixing tank 20 can include a flow-blocking structure. In one embodiment, the flow-blocking structure is a series of baffles 22. The baffles 22 can be made of a material such as polyvinyl chloride or any other suitable material compatible with the combined halogen solution produced in the system. The baffles 22 are designed to prevent the combined halogen solution from flowing through the tank 20 to provide the required mixing time. In one or more embodiments, the baffles 22 can include a plate or other conventional structure that can prevent or slow the flow of the combined halogen solution through the tank so that the solution flowing out of the tank 20 is thoroughly mixed. The mixing time is ideal to allow the chemical reaction between the hypochlorite ions from the tank 4 and the at least one halide ion from the tank 16 to be completed. The mixing time can be between 1 minute and 10 minutes.

[0039] Then, the fully reacted / mixed solution flows out of tank 20 along pipeline 24, where it passes through second sensor group 26 and enters tank 28. According to the embodiment, second sensor group 26 can be configured to measure at least pH, ORP or UV-Vis absorption curve of the diluted mixed halogen solution. However, second sensor group 26 can be configured to measure other solution parameters. The mixed halogen solution is transported away from tank 28 and enters pipeline 34 along pipeline 30 by the action of pump 32. Pipeline 34 can be configured to transport the mixed halogen solution to an application point (not shown). It will be appreciated by those skilled in the art that the application point can vary according to the specific circumstances of the water treatment process. In one or more embodiments, it can include cooling tower pools, swimming pool recirculation lines, etc.

[0040] The composition of the mixed halogen solution can be adjusted by controlling the chemical reaction between the hypochlorite ions from tank 4, the pH adjustment chemical from tank 8, and the at least one halogen ion from tank 16. The first sensor group 14 and the second sensor group 26 can be connected to a control system (not shown). The control system can control one or more features, including: (i) the flow rate of water entering pipe 2; and (ii) the pump speed of pumps 6, 10 and 18. Controlling the flow rate effectively controls the relative amount of chemicals added to the system 100, so that the correct amount of sodium bromide can be added to produce a solution of the desired composition. The control system can facilitate the production of a mixed halogen aqueous solution having a specific relative concentration of aqueous halogen species.

[0041] Alternatively, in another embodiment, non-chlorine halide ions and halogen-stabilizing compounds can be introduced simultaneously into a stream containing sodium hypochlorite. For example, tank 16 can contain a solution having at least one non-chlorine halide ion and at least one halogen-stabilizing compound, and the non-chlorine halide ions and the halogen-stabilizing compound are injected into the sodium hypochlorite stream present in pipeline 2. Adding at least one non-chlorine halide ion and at least one halogen-stabilizing compound simultaneously to the hypochlorite stream can have process benefits, such as simplifying the production of the desired mixed halogen solution. For example, according to one or more embodiments, the injection of the combined non-chloride halide solution and the halogen stabilizer only needs to control one injection, rather than having to independently control two inputs. In addition, by replacing two consumables with one consumable, this can simplify the logistics during the implementation of the present invention and can also reduce costs.

[0042] The above article about Figure 1 Many of the details discussed apply to Figure 2-4 For example, in Figure 2-4 In the present invention, the same numbers are used to refer to the same elements and perform the same functions. Therefore, for the sake of brevity, the following description will focus on Figure 1 The present embodiment discussed in the following reference Figure 2-4 The differences between the embodiments of the inventive concept are discussed.

[0043] Figure 2 An alternative embodiment of a system 200 is shown, which is configured to produce a stable mixture of aqueous halogens. Figure 1 As shown, the fully mixed combined halogen solution is piped through the pipeline 24 and passes through the second sensor group 26. Tank 66 contains an aqueous solution of at least one halogen stabilizing compound, which is injected into the pipeline 24 by the action of pump 68. The aqueous solution of at least one halogen stabilizing compound may include sodium sulfamate dissolved in water. However, according to one or more embodiments of the present invention, any other halogen stabilizing compound may be used, including but not limited to sulfamate, potassium sulfamate, taurine, glycine, hydantoin, 5,5-dimethylhydantoin, cyanuric acid or any combination thereof. The combined solution of the mixed halogen aqueous solution and the halogen stabilizing compound then enters the second mixing tank 70. The second mixing tank 70 includes a series of baffles 72 (similar to the mixing tank 22). The baffle 72 is configured to adjust the flow of the combined solution through the tank 70 to provide the required amount of mixing time. The mixing time is ideal to allow the chemical reaction between the mixed halogen aqueous solution and the halogen stabilizing compound introduced from the tank 66 to be completed.

[0044] The fully reacted / mixed solution then flows out of tank 70 along conduit 74, where it passes through a third sensor set 76. Depending on the embodiment, the third sensor set 76 may be configured to measure at least the pH, ORP, or UV-Vis absorption curve of the diluted hypochlorite solution. However, the third sensor set 76 may also be configured to measure other solution parameters. The stabilized solution then enters tank 78, where it may be discharged along conduit 80 to conduit 84 under the action of pump 82, from which it is transported to an application point (not shown).

[0045] Telemetry from the first, second and third sensor groups 14, 26 and 76 can be connected to a control system. The control system can control: (i) the flow of water into pipe 2; and (ii) the pumping rate of pumps 6, 10, 18, 68 and 82. Therefore, the system 200 is configured to optimally control the chemical reaction occurring between the hypochlorite ions from tank 4, the pH adjustment chemical from tank 8, the at least one halide ion from tank 16 and the at least one halogen stabilizing compound in tank 66. The control system promotes the production of a stable solution of mixed aqueous halogens having a specific relative concentration of aqueous halogen species and the stability of the aqueous halogen species. Controlling the flow rate effectively controls the relative amounts of chemicals added to the system 200, so that the correct amount of hypochlorite ions, sodium bromide and aminosulfonic acid (or other halogen stabilizer) can be added to produce a stable solution of the desired composition. That is, the composition of the solution is automatically and in real time adjusted by varying the amounts of combined hypochlorite, bromide (or non-chlorine halide), and sulfamic acid (or other halogen stabilizer) so that the final product / solution has the desired FAC content and free available bromine FAB content before being delivered to the point of application.

[0046] Figure 3 Another embodiment of a system 300 for producing a mixed halogen solution is shown, wherein an electrolytic cell or electrolytic system can be used to provide hypochlorite ions. As shown, the system 300 includes an on-site / in-situ electrolytic system / hypochlorite generation system 90 for generating a hypochlorite ion flow. Figure 1 Different from the implementation scheme described in Figure 3 The embodiment 300 described in the foregoing can be used to directly produce a stable hypochlorite solution using an electrolysis system 90. The system 300 involves electrolyzing a brine solution having at least one chloride-containing salt, preferably sodium chloride, and at least one halogen-stabilizing compound, preferably sulfamic acid. When such a brine is electrolyzed, a stable halogen solution is produced, which can then further react with bromide ions or iodide ions introduced into a solution downstream of the electrolysis system 90.

[0047] According to an embodiment, the hypochlorite ion concentration is about 3,000 mg / L or less than 3,000 mg / L. The remaining components and processes such as Figure 1 Therefore, for the sake of brevity, it will not be repeated here.

[0048] Alternatively, this embodiment can be used to simultaneously introduce non-chlorine halide ions and halogen-stabilizing compounds into a stream comprising sodium hypochlorite. For example, tank 16 can contain a solution containing at least one non-chlorine halide ion and at least one halogen-stabilizing compound, which is then injected into the sodium hypochlorite solution produced by electrolysis system 90. Simultaneous addition of at least one non-chlorine halide ion and at least one halogen-stabilizing compound to the hypochlorite stream can have process benefits, such as simplifying the production of the desired mixed halogen solution.

[0049] Figure 4 An embodiment of a system 400 for producing a stable mixed halogen solution is shown, wherein an on-site electrolysis system may be used to provide hypochlorite ions. In this embodiment, an on-site hypochlorite generation system 90 produces an aqueous hypochlorite ion stream, preferably at a hypochlorite ion concentration of about 3,000 mg / L or less. As shown in system 400, the on-site hypochlorite generation system 90 includes any conventional electrochemical cell configured to produce an oxidant solution containing at least one hypochlorite species by electrolyzing an aqueous salt having at least one halide-containing salt. The halide-containing salt used in the process is sodium chloride, although any salt containing at least one chloride ion component may be used. The remaining processes and components such as Figure 2 Therefore, for the sake of brevity, it will not be repeated here.

[0050] In one or more embodiments of the present invention, the mixing tank with internal baffles is intended to provide complete mixing of the aqueous halogen solution and provide sufficient time for any desired chemical reactions to occur. It will be apparent to anyone familiar with the art that other equivalent physical structures, such as mixing loops or in-line mixers, can be used for the same purpose as the baffles described herein.

[0051] In one or more embodiments of the present invention, the sensor group provides telemetry for controlling all aspects of the process to ensure that the desired results are achieved. For example, such a desired result can be the production of an aqueous solution having at least two halogen species with or without chemical stabilization. In one or more embodiments, the telemetry of the sensor group described herein is automatically transmitted to a control system. The control system monitors and analyzes one or more characteristics of the solution to adjust the composition of the solution, such as the ratio of bromine to chlorine and / or the ratio of stable halogen to free halogen. These features may include, but are not limited to, pH, temperature, oxidant concentration, oxidation / reduction potential (ORP), and ultraviolet absorption curve of the aqueous solution. The control system can be configured to automatically and in real time adjust the composition of the solution by adjusting functional aspects, such as: (i) flow rate; and / or (ii) injection rate of various chemicals used in the process, for example, changing the combined amount of hypochlorite ions, bromide (or other non-chlorine halides) ions, and aminosulfonic acid (or other halogen stabilizers). Controlling these aspects ensures that the final product / solution has the desired free available chlorine (FAC) and free available bromine (FAB) content before being delivered to the point of application. Therefore, the telemetry provided by the sensor array can be used to directly or indirectly provide information about the composition of the solution, including the halogen species present and the degree of stability.

[0052] For example, the sensor can be used to measure the UV-Vis absorption curve of the aqueous halogen solution produced in one or more embodiments. Since different aqueous halogen species have different UV-Vis absorption curves, remote sensing from the sensor can be used to determine the relative concentrations of aqueous halogens and stable aqueous halogens present in the solution. For example, Figure 7 As shown, the relative intensity of the two peaks can be used to determine the amount of bromine and chlorine in the product solution. The sensor measures the absorption curve of the product solution and transmits it to the control system. The control system may include a processor and a memory. The processor is configured to process the software loaded in the memory to associate the absorption curve with the predetermined data of the composition of the desired product solution. In one or more embodiments, the measured pH or ORP can be associated with the predetermined data of the composition of the desired product solution. The control system can then use this data to inject more or less bromide, for example, depending on how much bromine is needed in the final product solution.

[0053] Aqueous halogens and stable aqueous halogen species that can be measured using one or more embodiments include dissolved molecular chlorine, dissolved molecular bromine, dissolved molecular iodine, hypochlorous acid, hypobromous acid, hypoiodous acid, hypochlorite ion, hypobromite ion, hypoiodite ion, N-chlorosulfamate, N-bromosulfamate, N-iodosulfamate, N-chlorosulfamate, N-bromosulfamate, N-iodosulfamate, N-chlorotaurine, N-bromotaurine, N-iodotaurine, N,N-dichlorotaurine, N,N-dibromotaurine, N,N-diiodotaurine, N-bromo-N-chlorotaurine, N-bromo-N-iodotaurine, N-chloro-N-iodotaurine, 1-chloro- 5,5-dimethylhydantoin, 1-bromo-5,5-dimethylhydantoin, 1-iodo-5,5-dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin, 1,3-diiodo-5,5-dimethylhydantoin, 1-chloro-3-bromo-5,5-dimethylhydantoin, 1-chloro-3-iodo-5,5-dimethylhydantoin, 1-bromo-3-chloro-5,5-dimethylhydantoin, 1-bromo-3-iodo-5,5-dimethylhydantoin, 1-iodo-3-chloro-5,5-dimethylhydantoin, 1-iodo-3-bromo-5,5-dimethylhydantoin or a combination thereof.

[0054] Figure 5Another embodiment of the present invention is shown. This embodiment discloses a process for diluting the final product stream so that the composition of the mixed halogen solution can be characterized using UV-Vis spectroscopy. As shown, pipeline 180 conveys the entire / main flow of the solution to be analyzed. Valve 182 is configured to transfer a small side stream, and its flow rate is preferably less than or equal to 1% of the total flow rate in pipeline 180. In one or more embodiments, its flow rate is about about 0.1% to about 1% of the total flow rate. This side stream of the mainstream is transported to analyzer 186 along pipeline 184 for analysis. Dilution water is transported along pipeline 188, in which it is combined with pH adjustment chemicals (such as sodium hydroxide) contained in tank 190. The pH value of the solution has an impact on the absorption spectrum of aqueous halogen. Therefore, the pH of the solution is controlled to ensure that the pH of the dilute solution will not be reduced to the extent of interfering with the spectral curve measurement of the solution to be analyzed. In one or more embodiments, the pH can exceed 10, preferably exceed 11. Before entering analyzer 186, the dilute solution is injected into pipeline 188 by the action of pump 192. pH adjusting chemicals are added to ensure that the pH of the dilution water matches the pH of the solution to be analyzed. Within analyzer 186, the flows from conduits 184 and 188 are combined so that the concentration of the total oxidant contained in the diluted solution is between 50 and 250 mg / L. The combined liquid flow then passes through a UV sensor that is configured to measure the absorbance of the solution in the range of 200 to 800 nm. The combined liquid flow then leaves analyzer 186 along conduit 194 and enters valve 196, where the solution is combined with the total original liquid flow from pipeline 180.

[0055] The control system used in one or more embodiments is configured to further prevent the formation of undesirable byproducts of various chemical reactions. For example, it is known that under certain reaction conditions, the reaction between hypochlorite ions and bromide ions can result in the formation of bromate ions (BrO 3 - ), particularly when the reaction is carried out at a pH value of less than 10. Therefore, one function of the sensor group used in this embodiment is to ensure that the pH of the hypochlorite ion solution is adjusted to greater than 10 before introducing additional halide ions.

[0056] Figure 6The embodiment of system 600 is shown, it has electrolytic process to produce the solution with mixed free halogen, then stabilizes the solution with mixed free halogen by adding halogen stabilizing compound.In this embodiment, pipeline 201 is used for water delivery to system 600 by pump mode (not shown).Tank 202 comprises the solution with at least one halogen-containing salt dissolved in water.According to the embodiment, at least one halogen-containing salt dissolved in water is sodium chloride.However, it should be understood that any halogen-containing salt can be potentially used in this embodiment or other embodiments.Pump 204 is used for the solution contained in tank 202 to be delivered to pipeline 201.

[0057] Tank 206 contains a solution composed of a second halide-containing salt having halide ions different from the halide ions in the salt dissolved in the water in tank 202. According to an embodiment, the second halide-containing salt dissolved in the water in tank 206 is sodium bromide, according to this embodiment, however any salt containing halide ions different from the halide ions in the salt dissolved in the water in tank 202 may be used. Pump 208 is used to transfer the solution contained in tank 206 to pipeline 200.

[0058] In one embodiment, the pH of the solution can be adjusted at this stage. For example, tank 210 contains a solution having at least one pH adjusting chemical dissolved in water. According to an embodiment, the pH adjusting chemical dissolved in the water in tank 210 is sodium hydroxide. However, it should be understood that according to this embodiment, any chemical capable of adjusting the pH of an aqueous solution can be used. Pump 212 is used to transfer the solution contained in tank 210 to pipeline 201. The combined solution then passes through an in-line static mixer 214, passes through a sensor group 216, and enters an electrolysis system 218.

[0059] According to an embodiment, the sensor group 216 is configured to measure at least the pH of the diluted hypochlorite solution. However, the sensor group 216 can be configured to measure other solution parameters. The sensor group 216 can ensure that the mixed halide brine contained in the pipeline 200 is at a desired pH, and the telemetry from the sensor group 216 is sent to a control system (not shown), which is configured to use the pump 212 to change the amount of pH adjustment chemical injected from the tank 210 into the pipeline 200.

[0060] The electrolysis system 218 includes an electrolysis cell (not shown) that can electrolyze the mixed halide brine to produce a solution having mixed aqueous halogens. The solution flows out of the electrolysis system 218 along the pipe 220 and passes through the second sensor group 220. According to an embodiment, the sensor group 220 is configured to measure at least the pH, ORP or UV-Vis absorption curve of the diluted hypochlorite solution. However, the sensor group 220 can be configured to measure other solution parameters.

[0061] Tank 224 comprises a solution having at least one halogen-stabilizing compound dissolved in water. According to an embodiment, at least one halogen-stabilizing compound dissolved in water in tank 202 is sulfamic acid, but any halogen-stabilizing compound or its mixture may also be used. Pump 226 may be used to transfer the solution contained in tank 224 to pipeline 220. The combined solution then enters a mixing tank 228 comprising a series of baffles 230. Baffles 230 are configured to regulate the flow of solution through the tank to provide the required mixing time amount. This mixing time is ideal, to allow the chemical reaction occurring between the halogen aqueous solution mixed and the halogen-stabilizing compound introduced from tank 224 to be completed.

[0062] The fully reacted solution then flows out of tank 228, where it passes through a third sensor set 232. According to an embodiment, sensor set 232 is configured to measure at least pH, ORP, or UV-Vis absorption curve of the diluted hypochlorite solution. However, sensor set 232 may also be configured to measure other solution parameters.

[0063] The telemetry provided by the sensor group 232 is preferably used to measure the properties of the solution to ensure that the desired stable halogen solution has been achieved. The telemetry from the sensor group 232 is also used by a control system not specifically shown herein to control various aspects of the system, such as the flow rate and injection rate of the halogen stabilizing compound solution contained in the tank 224 to ensure that a stable halogen solution is obtained. The solution then enters the tank 234, where it is discharged along the pipeline 236 to the pipeline 240 by the action of the pump 238, where the solution is transported to the application point.

[0064] Example

[0065] Various examples are provided below. The data in these examples provide correlations between measured and monitored solution properties, such as ORP and pH, and the bromine and chlorine and stable and unstable halogen compositions of the solution.

[0066] Example 1

[0067] Sodium hypochlorite solution was prepared using an on-site hypochlorite generation system by electrolysis of sodium chloride brine to obtain a solution with a free available chlorine (FAC) concentration of 3450 mg / L, a pH of 8.94, and an oxidation reduction potential (ORP) of 813 mV. Four 200 ml samples of this solution were prepared and reacted with 0.1, 0.2, 0.4, and 2.0 g of sodium bromide to produce a series of mixed halogen solutions. The pH, ORP, FAC content, and free available bromine (FAB) content of each solution were measured and recorded in the table below.

[0068] Table 1

[0069]

[0070] Example 2

[0071] Sodium hypochlorite solution was prepared using an on-site generation system by electrolysis of sodium chloride brine. After electrolysis, the pH of the solution was adjusted to 11.16 by adding sodium hydroxide to obtain a solution with a FAC concentration of 3375 mg / L and an ORP of 427 mV. Four 200 mL samples of this solution were prepared and reacted with 0.098, 0.2, 0.398 and 1.98 g of sodium bromide to produce a series of mixed halogen solutions. The pH, ORP, FAC content and FAB content of each solution were measured and recorded in the table below. The initial sodium hypochlorite solution as well as the product solution were diluted with deionized water to a FAC concentration of 95-105 mg / L, and the ultraviolet-visible (UV-Vis) absorption spectra of the resulting solutions were recorded. Figure 7 A graph showing the variations of these spectra over the wavelength range of 225 to 450 nm is given.

[0072] Table 2

[0073]

[0074]

[0075] Example 3

[0076] An aqueous chlorine solution with a FAC concentration of 3800 mg / L was prepared by electrolysis. The ORP value of this solution was measured to be 795 mV and the pH was 9.04. Three 200 mL samples of this solution were prepared and reacted with 0.3, 1.3 and 2.6 g of sodium sulfamate to produce a sulfamate-stabilized halogen solution. The pH, ORP, FAC content, FAB content and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0077] Table 3

[0078]

[0079] Example 4

[0080] A mixed halogen aqueous solution consisting of aqueous chlorine and aqueous bromine was prepared by adding 0.76 g of sodium bromide to 700 mL of an aqueous chlorine solution having a FAC concentration of 3800 mg / L prepared by electrolysis. The ORP value of the solution was measured to be 796 mV and the pH was 9.26. Three 200 mL samples of this solution were prepared and reacted with 0.3, 1.3 and 2.6 g of sodium sulfamate to produce a halogen solution stabilized by sulfamate. The pH, ORP, FAC content, FAB content and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0081] Table 4

[0082]

[0083] Example 5

[0084] A mixed halogen aqueous solution consisting of aqueous chlorine and aqueous bromine was prepared by adding 7.6 g of sodium bromide to 700 mL of an aqueous chlorine solution having a FAC concentration of 3800 mg / L prepared by electrolysis. The ORP value of the solution was measured to be 786 mV and the pH was 9.68. Three 200 mL samples of this solution were prepared and reacted with 0.3, 1.3 and 2.6 g of sodium sulfamate to produce a halogen solution stabilized by sulfamate. The pH, ORP, FAC content, FAB content and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0085] Table 5

[0086]

[0087] Example 6

[0088] An aqueous chlorine solution with a FAC concentration of 3600 mg / L was prepared by electrolysis, the pH was adjusted to 10.98, and the ORP value of the resulting solution was 585 mV. Three 200 mL samples of this solution were prepared and reacted with 0.25, 1.3, and 2.5 g of sodium sulfamate to produce a sulfamate-stabilized halogen solution. The pH, ORP, FAC content, FAB content, and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0089] Table 6

[0090]

[0091] Example 7

[0092] A mixed halogen aqueous solution consisting of aqueous chlorine and aqueous bromine was prepared by adding 0.72 g of sodium bromide to 700 mL of an aqueous chlorine solution having a FAC concentration of 3600 mg / L prepared by electrolysis. The reaction between hypochlorite and bromide was allowed to proceed to completion, and then the pH of the mixed halogen solution was adjusted to 10.85. The ORP value of the solution was 649 mV. Three 200 mL samples of this solution were prepared and reacted with 0.25, 1.3, and 2.5 g of sodium sulfamate to produce a halogen solution stabilized by sulfamate. The pH, ORP, FAC content, FAB content, and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0093] Table 7

[0094]

[0095] Example 8

[0096] A mixed halogen aqueous solution consisting of aqueous chlorine and aqueous bromine was prepared by adding 7.2 g of sodium bromide to 700 mL of an aqueous chlorine solution having a FAC concentration of 3600 mg / L prepared by electrolysis. The reaction between hypochlorite and bromide was allowed to proceed to completion, and then the pH of the mixed halogen solution was adjusted to 10.83. The ORP value of the solution was 657 mV. Three 200 mL samples of this solution were prepared and reacted with 0.25, 1.3, and 2.5 g of sodium sulfamate to produce a halogen solution stabilized by sulfamate. The pH, ORP, FAC content, FAB content, and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0097] Table 8

[0098]

[0099] Example 9

[0100] A mixed halogen aqueous solution consisting of sodium hypochlorite and N-chloroaminosulfonic acid was prepared by electrolyzing a saturated sodium chloride brine containing 50 g / L aminosulfonic acid. The pH of the mixed halogen solution was 11.15 and the TC concentration was 2475 mg / L. Four 200 mL samples of this solution were prepared and reacted with 0.101, 0.205, 0.410 and 2.043 g of sodium bromide to produce a series of mixed halogen solutions. The pH, FAC content and FAB content of each solution were measured and recorded in the table below.

[0101] Table 9

[0102]

[0103] Example 10

[0104] A mixed halogen aqueous solution consisting of sodium hypochlorite and N-chloroaminosulfonic acid substances was prepared by electrolysis of saturated sodium chloride brine containing 100 g / L aminosulfonic acid. The pH of the mixed halogen solution was found to be 11.03 and the TC concentration was 3725 mg / L. Four 200 mL samples of this solution were prepared and reacted with 0.116, 0.235, 0.469 and 2.337 g of sodium bromide to produce a series of mixed halogen solutions. The pH, FAC content and FAB content of each solution were measured and recorded in the table below.

[0105] Table 10

[0106]

[0107] Embodiment 11

[0108] An aqueous chlorine solution with a FAC concentration of 3625 mg / L was prepared by electrolysis. The ORP value of this solution was measured to be 804 mV and the pH value was 8.96. Nine 200 mL samples of this solution were prepared and sodium bromide and sodium sulfamate dissolved in 20 mL of water were reacted before adding to the initial aqueous chlorine solution. The pH, ORP, FAC content, FAB content and total chlorine (TC) content of each solution were measured and recorded in the table below.

[0109] Table 11

[0110]

[0111] Therefore, the present invention is well suited to achieve the objects and advantages mentioned and inherent therein. The foregoing description is not intended to limit the present invention, and the present invention may be used according to different aspects or embodiments without departing from the scope of the present invention. Discussions of acts, steps, chemicals, devices, assemblies, elements, etc. are included in this specification merely to provide a background for the present invention. There is no suggestion or representation that any or all of these contents form part of the prior art base or are common general knowledge in the field relevant to the present invention.

[0112] In addition, the specific illustrative embodiments disclosed above may be changed or modified, and all such changes are considered to be within the scope and spirit of the invention. Although the systems and methods are described in terms of "comprising", "containing" or "including" various devices / components or steps, it should be understood that the systems and methods may also be described by "essentially consisting of" or "consisting of" various components and steps. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, each numerical range disclosed herein (in the form of "from about a to about b", or equivalently, "from approximately a to b") should be understood to set forth each numerical value and range contained in the wider numerical range. If there is any conflict in the usage of words or terms in this specification, claims, and one or more patents or other documents that may be incorporated herein by reference, the definition consistent with this specification should be adopted.

Claims

1. A system for producing a mixed halogen aqueous solution having at least two different halogen substances, comprising the following components: An in-situ device for generating an aqueous hypochlorite solution; A first storage tank configured to contain an aqueous halogen solution, and wherein the aqueous halogen solution is chlorine-free; A first mixing tank downstream of the first storage tank, wherein the first mixing tank includes a flow-blocking structure; and A pipeline for delivering a stream of the aqueous hypochlorite solution to the first mixing tank; A second storage tank containing the aqueous hypochlorite solution, wherein the aqueous hypochlorite solution is delivered from the second storage tank to the first mixing tank using a pipeline, and wherein the second storage tank is located upstream of the first mixing tank; A third storage tank for storing pH-adjusting chemicals; A static mixer; A first sensor group, wherein the first sensor group incorporates one or more sensors for measuring at least the pH of the aqueous hypochlorite solution before it is piped to the first mixing tank; A second sensor group downstream of the first mixing tank, wherein the second sensor group includes one or more sensors for measuring one or more parameters of the mixed halogen aqueous solution; the parameters are selected from the group consisting of pH, redox potential, UV-Vis absorption curve, and combinations thereof.

2. The system according to claim 1, wherein the aqueous hypochlorite solution is delivered from the in-situ device using a pipeline, and wherein the in-situ device is located upstream of the first mixing tank.

3. The system according to claim 1, wherein the static mixer is used to mix the aqueous hypochlorite solution with the pH-adjusting chemicals before the aqueous hypochlorite solution is piped to the first mixing tank.

4. The system according to claim 1, wherein the first sensor group includes at least a pH sensor for measuring the pH of the pH-adjusted aqueous hypochlorite solution before the pH-adjusted aqueous hypochlorite solution is delivered to the first mixing tank.

5. The system according to claim 1, wherein the flow-blocking structure includes one or more baffles, and wherein the baffles are configured to facilitate (a) the aqueous hypochlorite solution or the pH-adjusted aqueous hypochlorite solution and (b) the chlorine-free aqueous halogen solution to be thoroughly mixed to produce a mixed halogen aqueous solution having at least two different halogen substances.

6. The system according to claim 5, wherein the aqueous halogen solution is a bromine-containing fluid.

7. The system according to claim 1, wherein the aqueous halogen solution includes bromine and iodine.

8. A method for producing a mixed halogen aqueous solution having at least two different halogen substances, comprising: Pumping a stream of the aqueous hypochlorite solution to a first mixing tank; Pumping the aqueous halogen solution to the first mixing tank, wherein the aqueous halogen solution is chlorine-free; and Facilitating thorough mixing of the aqueous hypochlorite solution and the chlorine-free aqueous halogen solution in the first mixing tank to produce a mixed halogen aqueous solution having at least two different halogen substances; It further includes (i) measuring at least the pH of the aqueous hypochlorite solution before the aqueous hypochlorite solution is delivered to the first mixing tank; and (ii) Measuring one or more parameters of the aqueous mixed halogen solution, wherein the parameters are selected from the group consisting of pH, redox potential, UV-Vis absorption curve, and combinations thereof; Further comprising processing the measured values to control the flow rate of the aqueous hypochlorite solution to the first mixing tank; Further comprising processing the measured values to control the pumping rate of the aqueous hypochlorite solution and / or the aqueous halogen solution, thereby controlling the reaction between hypochlorite ions and non-chlorine halide ions.

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