MX2008014300A - Electrolytic apparatus with polymeric electrode and methods of preparation and use. - Google Patents

Abstract

The invention provides low cost methods and apparatus that utilize at least one carbon-filled polymeric electrode to electrolytically generate desirable products.

Description

ELECTROLYTIC APPARATUS WITH POLYMERIC ELECTRODE AND METHODS OF PREPARATION AND USE FIELD OF THE INVENTION This invention relates to electrolytic apparatus having at least one polymeric electrode and to methods of construction and use thereof, and in particular to electrolytic apparatus comprising at least one polymeric electrode that generates electrolytically oxidants BACKGROUND OF THE INVENTION Disinfection solutions generated in electrolytic form have been described. For example, Barger et al., In US Patent No. 6,255,270, describes cleaning and disinfecting compositions with an electrolyte disinfection enhancer. Tremblay, et al., In the North American Patent Application Publication No. 2003/0042134, discloses a high efficiency electrolysis cell for generating oxidants in solutions. In fact, Logan, in US Patent No. 2,163,793, describes producing chlorine dioxide electrolytically. Kadlec, et al., In U.S. Patent No. 6,869,518, describes the electrochemical generation of chlorine dioxide. Chen et al., In the North American Patent No. 6,921,521, discloses a method for producing chlorine dioxide using alkali chlorate in an acidic mineral medium and urea as a reducing agent. Scheper, et al., In US Patent No. 6,921,743 disclose automatic dishwashing compositions containing a halogen dioxide salt and methods for use with electrochemical cells and / or electrolytic devices. Price, et al., In the North American Patent Application Publication No. 2003/0213503, describes electrochemical methods based on signals for automatic dishwashers. Scheper, et al., In the North American Patent Application Publication No. 2003/0213704 discloses a self-powered self-powered electrolytic device for improved performance in automatic dishwashing. Herrington, in US Patent No. 7,008,523 discloses an electrolytic cell for surface disinfection and point of use. Tremblay, et al., In the North American Patent Application Publication No. 2004/0149571, discloses an electrolytic cell for generating halogen dioxide in an apparatus. Tremblay, et al, in US Patent No. 7,048,842 discloses an electrolytic cell for generating chlorine dioxide. Roensch, et al., In U.S. Patent No. 7,077,995, discloses a method for treating aqueous systems with locally generated chlorine dioxide.

SUMMARY OF THE INVENTION According to one or more embodiments, the invention relates to an electrolytic apparatus comprising an electrolytic cell having at least one polymeric electrode filled with carbon. According to one or more embodiments, the invention relates to a method comprising providing an electrolytic cell having at least one polymer electrode charged with carbon.

BRIEF DESCRIPTION OF THE FIGURE The attached figure is not intended to be a scale figure. For purposes of clarity, no component can be labeled in the figure. In the figure, FIGURE 1 illustrates an electrolytic apparatus according to one or more embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention can provide an electrolytic apparatus, systems using one or more electrolytic apparatuses, as well as techniques involving such electrolytic devices. According to some aspects, one or more embodiments of the invention involve electrolytic devices having at least one polymeric electrode. In some cases, the electrolytic device of the invention may comprise a plurality of polymeric electrodes. For example, the electrolytic device may have at least one electrode that serves as a cathode comprised of a polymeric material and, optionally, one or more electrodes that serve as an anode comprising the same or different polymeric material. In some cases, the polymeric electrode can be considered to be charged with electrically conductive components. In some aspects, the invention provides relatively low cost components compared to conventional electrodes but with comparable performance. The polymer electrode can be a polymeric electrode filled with carbon. Additional embodiments may involve using other components that facilitate the conduction or transport of an applied electric current through one or more polymeric electrodes of the apparatus of the invention. The polymer electrode may further comprise one or more cores or electrical components that provide electrical conductivity through the electrode body. For example, the electrolytic cell can have an anode and a cathode, either or both can be a polymeric electrode with at least one metal core integrated therein. The metal core thus serves to conduct electrically current and reduces the probability of a resistive gradient across the electrode. The electrolytic devices of the invention can be used for an electrocatalytic generation of one or more products from one or more precursor species. Some aspects of the invention involving the various electrolytic devices of the invention can be directed to generate oxidizing species. In particular, some aspects of the invention may involve electrolytically generating one or more halogenated oxidizing agents. For example, one or more electrolytic embodiments of the invention may involve electrolytically generating a chlorinated, brominated or fluorinated compound, or mixtures thereof, which may oxidize one or more target compounds, non-limiting examples of which include bacteria. According to some particularly advantageous embodiments, the various electrolytic embodiments of the invention can be used to generate one or more of chlorine, ichlorous species, and chlorine dioxide. In addition, some embodiments of the invention provide an oxidizing species that may be present or carried in a disinfecting solution generated in situ, typically for immediate distribution and use. As used herein, "disinfection" refers to at least partially returning organisms that are biologically inactive or inert or incapable of further reproduction or spread of colonies. Additional particular embodiments of the invention involve providing an electrolytic apparatus comprising at least one polymeric electrode. The following discussion involves the generation of chlorine dioxide but the invention is not limited to that and can be used to generate other desirable species. The electrolytic apparatus, exemplified in FIGURE 1, in one or more embodiments of the invention may have one or more electrolytic cells 110, one or more of which may comprise at least one cathode 112 and at least one anode 114. The electrolytic apparatus 100 may further comprise one or more sources of electrolytes in fluid communication or at least capable of being in fluid communication with the electrolytic cell 110. A plurality of sources of electrolytic fluids can be used to flexibly provide functionalities selectively chosen by an operator of the apparatus. Thus, for example, the electrolytic apparatus may comprise a first or primary source of a first electrolyte comprising one or more precursor compounds and an alternative or supplemental source of a second electrolyte comprising one or more alternative precursor compounds. The electrolyte may further comprise at least one oxidizing agent selected from the group consisting of chlorates, perchlorates, hypohalites, permanganates, chromates and peroxides. In other cases, the electrolyte may consist of or essentially consist of a halite or halide such as a chloride or a salt of hydrochloric acid. The electrolytic cell can be fluidically connected to a source of electrolytic fluid through the inlet port 102. The cell 110 further comprises at least one output port 104 for distribution of a product generated at a point of use. The cell 110 has a body 114 which contains a cavity 106 which during the operation is filled with the electrolyte from one or more electrolyte sources having at least one precursor species therein. The cell 110 further has an anode 112 connected to a power source 130. The body 114 can also serve as a cathode and is illustrated as being electrically connected to the power source 130 through one or more metallic conductive cores 115, at least partially integrated within the body 114. Typically, a member 120 can electrically secure and isolate the anode 112 of the cathode body 114. Thus, some electrolytic cells of the invention may comprise a body 114 which serves to contain electrolyte and facilitates the electrolytic conversion of a precursor compound to one or more generated oxidizing compounds. In alternative embodiments, the body of the electrolytic cell can serve as the anode. This aspect of the invention facilitates the production of the electrolytic cell especially where polymeric materials are used. Thus, some aspects of the invention may provide a meltable or moldable electrode configured to contain electrolyte. During the operation, an applied current is conducted through the electrolytic cell to generate one or more desired compounds from one or more precursor compounds in the electrolytic fluid transferred in the cell. For example, chlorine dioxide can be generated at or near an electrode, typically at or near the anode, of the electrolytic cell, from a precursor chloride species in the electrolyte. In some particular embodiments of the invention, the halite compounds can be converted electrolytically to provide a disinfecting or deodorizing solution comprising chlorine oxide. Other suitable desirable or secondary reactions can be facilitated including those that generate hypochlorous type species, chlorine and other oxidizing species. As noted herein, however, secondary oxidant species may also be present in the electrolyte. The electric current can be provided by one or more electrical sources. In some cases, the electrical source provides a direct current potential of less than about 6 volts but in some cases, less than about 4.5 volts and still in other cases, less than about 3 volts. Depending on the service, lower potentials can be used to provide sufficient generation of the desired product. Typically, however, a minimum potential such as at least about 2 volts may be preferred to provide at least partial conversion of the precursor compounds to one or more desirable oxidant products. Particularly advantageous embodiments of the electrical source may involve conventional primary cells such as zinc-carbon, alkaline or lithium-based cells or electrochemical batteries as well as secondary or rechargeable batteries, such as, but not limited to, nickel cadmium or nickel metal cells. hydride or lithium ion. Preferably, the electrical source may comprise one or more cells such as those having size designations of "AA", "AAA", "C" and "D".

Where the electrolytic apparatus comprises a plurality of electrolytic cells, one or more of at least one of the electrolytic fluid sources can be fluidically connected or connected to any of the electrolytic cells. In some embodiments of the invention, one or more components of the electrolytic apparatus can be removed and replaced. For example, the electrolyte source can be removed, accessed or otherwise filled with new electrolyte. Similarly, the power source can be replaced or recharged or otherwise re-energized and therefore additionally provide an electric current for the cell. At least a portion of the generated product solution can then be used to at least partially disinfect or deodorize a point of use such as a surface. The distribution of the product solution comprising one or more generated oxidizing agents can be effected using any suitable technique. For example, the disinfectant or deodorizing solution generated can become airborne as an aerosol or be sprayed on at least a portion of the desired surface to be decontaminated. In other cases, the generated solution comprising one or more oxidizing agents can be transferred in a bath comprising the same or different desirable oxidizing agents. The target article can then be immersed therein to facilitate oxidation or non-activation of the target compounds by one or more oxidizing species. The polymeric electrode can use any suitable bonding component or matrix. For example, the electrode may comprise thermoplastic or thermoset polymeric materials with electroconductive or electroactive components, non-limiting examples include graphite and electrically conductive carbon. The polymer electrode can be formed by injection molding or similar techniques used to make polymer components. In fact, the molding ability of polymeric materials can provide low cost electrodes having increased surface areas, with respect to electrodes not based on conventional polymers, whereby it reduces the effective current density and, in some cases, lowers the operating voltage. For example, polymeric electrodes can be configured to have ridges that increase the effective surface area. In addition, improved cell fluid dynamics can be realized by melting at least a portion of the cell with smooth surfaces and a surface profile that improves mass transfer through the cell, and in some cases, also reduces any holding of precipitation of limestone deposits. Non-limiting examples of polymeric binders include polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, polyethylene terephthalate, polyvinyl chloride, polycarbonate, nylon, polymethyl methacrylate, and mixtures or copolymers thereof. The polymeric binder may further comprise reinforced agents such as fibers. In some cases, the reinforcement component can also serve to facilitate electrical conductivity. For example, the electrode may comprise a metallic reinforcing core, comprised of for example copper, connected to the power source. In some cases, at least a portion of the polymer electrodes may further comprise an electrocatalytic coating. Non-limiting examples of which include valve metals, precious metals, metals of the platinum group, as well as their oxides and mixtures thereof. Other coating materials that can be used include, for example, Co02 and Mn02. The electrode can also use a crosslinked or mesh substrate in the molded electrode. For example, the polymeric material can be molded with a titanium mesh. The conductive characteristics of the cell can be improved by providing additional electrical contact points for example, when using high pressure point and also when using reticulated structures to further improve the contact characteristics. The crosslinked structures may be comprised of, for example, copper, nickel, aluminum and silver. The various systems and techniques of the invention can be used in different applications in the chlorine dioxide-generating embodiments described in exemplary form including, for example, in electrochlorination, generation of mixed oxidants, and pool gilders. Other applications include the use as electrodeionization cathodes.

EXAMPLES The function and advantages of these and other embodiments of the invention can be further understood from the following examples, which illustrate the benefits and / or advantages of one or more systems and techniques of the invention but do not exemplify the full scope of the invention. the invention.

EXAMPLE 1 This example compares the performance of an electrolytic cell comprising a carbon loaded polyethylene electrode, from Covalence Specialty Materials Corp. (Franklin, Massachusetts), with respect to a cell with a bare titanium electrode. The anode in both cells was a titanium mesh electrode with OPTIMA® electroactive coating RUA-SW from Siemens Corporation (Union, New Jersey). The electrode gap was 2 mm. The electrolyte solution used was 1 M sodium chloride. Table 1 lists the potential measured at various operating current densities. The data show a higher specific resistivity of the carbon-charged polyethylene electrodes with respect to the titanium cathodes.

Table 1. Voltage of the cell measured in volts, using a polyethylene cathode loaded with carbon or a cathode of titanium.

Example 2 In this example, the polymeric electrodes of Example 1 were modified to improve performance by using metallic components, four aluminum bars, and having several contact points. The anode used was a titanium sheet with OPTIMA® RUA electroactive coating, from Siemens Corporation. The air gap of the electrodes was 1.6 mm and the electrolyte solution was 1 M sodium chloride. Table 2 lists the potential measured with several points of contact and shows that increased points of contact can improve the characteristics of the cell because the carbon load in some cases, can be considered as polyethylene filled with carbon particles in contact with each other to provide a conductive path and toward the electrode surface.

Table 2. Measured potential of the cell using a polyethylene cathode loaded with carbon with several contact points.

Example 3 This example shows the performance of a cell using a polyethylene cathode charged with carbon of Example 1 and further comprises a cross-linked structure of silver to facilitate electrical conduction. The anode was comprised of a titanium sheet catalyzed with OPTIMA® RUA coating. The air gap of the electrodes was 1.6 mm and the electrolyte was 1 M sodium chloride.

Table 3 lists the potential measured with and without the crosslinked conductor and shows the improved performance.

Table 3. The measured potential of the cell using a polyethylene cathode loaded with carbon with or without a crosslinked conductor.

Example 4 To further improve performance, the carbon-charged polyethylene cathode of Example 1 was treated with agents that reduce surface tension. The anode used was a titanium sheet catalyzed with OPTIMA® RUA coating. The air gap of the electrodes was 1.6 mm and the electrolyte was sodium chloride. The carbon-charged polyethylene cathode was used with two aluminum bars and two cross-linked foam silver strips, and the data presented in table 4 show that such components facilitate electrical contact by lowering the potential of the cell.

Table 4. Measured potential of the cell using a polyethylene cathode loaded with carbon with various surface treatments.

Example 5 In this example, an alternative carbon-based GRAFCELL® graphite plate from GrafTech International Ltd. (Parma, Ohio) was used as the cathode. It is believed that the higher carbon content, with respect to the carbon loaded electrode, should provide improved specific resistivity, and lower contact resistance. The anode was comprised of the titanium sheet catalyzed with OPTIMA® coating. The air gap of the electrodes was 1.6 mm and the electrolyte solution was sodium chloride. Table 5 shows the performance of this configuration.

Table 5. Cell performance using GRAFCELL® graphite plate cathode over time.

Example 6 In this example, the anode and the cathode of Example 4 were modified to evaluate alternative contact configurations. As in Example 4, the anode comprised of the titanium sheet and catalyzed with the OPTIMA® coating was sandblasted and two were connected at two points of contact, without using aluminum contact rods. The GRAFCELL® graphite plate cathode was configured similarly to have two points of contact. A titanium sheet was also used to provide a comparative base. Table 6 lists the potentials measured at various current densities using the GRAFCELL® graphite sheet cathode and the titanium sheet cathode. The electrolyte was 3 M sodium chloride solution. The GRAFCELL® sheet was pre-treated for 40 hours at 0.5 A / m2. The data shows the comparable performance between the graphite sheet cathode and the conventional titanium cathode.

Table 6. Cell potential, in volts, using a GRAFCELL® graphite plate cathode compared to the titanium cathode.

Example 7 In this example, the cell was assembled using GRAFCELL® graphite sheet as the cathode and also as the anode. The air gap of the electrodes was 1.6 mm and the solution was sodium chloride. At 0.2 kA / m2, the operating potential was 3.37 volts. This example in this way shows that cells comprising electrodes charged with carbon can be used according to some aspects of the invention.

Example 8 In this example, the cell as in Example 7 was further modified by plating the graphite sheet anode. Under the same operating configuration, the operating voltage was measured to be approximately 2.99 volts, thereby lowering the overvoltage potential. Having now described some illustrative embodiments of the invention, it should be apparent to those skilled in the art that the foregoing is only illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention. For example, the anode of the electrolytic cell may comprise a polymeric material filled with carbon. In particular, although many of the examples presented here involve specific combinations of acts of methods or elements of systems, it must be understood that those acts and those elements can be combined in other ways to achieve the same objectives. Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that current parameters and / or configurations will depend on the specific application in which the systems and techniques of the invention are used. Those skilled in the art should also recognize or be able to ensure, using no more than routine experimentation, equivalents to the specific embodiments of the invention. Therefore, it will be understood that the embodiments described herein are presented by way of example only and that, within the scope of the appended claims and equivalents thereto; the invention can be practiced in another way than that which is specifically described. In addition, it should also be appreciated that the invention is directed to each feature, system, subsystem or technique described herein and any combination of two or more features, systems, subsystems or techniques described herein and any combination of two or more features. , systems, subsystems and / or methods, if such features, systems, subsystems and techniques are not mutually inconsistent, it is considered to be within the scope of the invention as represented in the claims. further, acts, elements and characteristics discussed only together with a modality are not intended to be excluded from a similar role in other modalities. As used herein, the term "plurality" refers to two or more elements or components. The terms "comprising", "including", "carrying", "having", "containing" and "involving", whether in the written description or in the claims and the like, are indefinite terms, is say, to mean that "include but are not limited to". Thus, the use of such terms is used to encompass the elements listed after this, and equivalents thereof, as well as additional elements. Only the transition phrases "consisting of" and that "consisting essentially of" are closed or semi-closed transition phrases, respectively with respect to the claims. The use of ordinal terms such as "first", "second", "third", and the like in the claims to modify an element of the claim does not imply by itself any priority, precedence or order of one claim element over another or the temporal order in which acts of a method are performed, but are used only as labels to distinguish a claim element having a certain name different from the element having the same name (except for the use of the ordinal term) to distinguish the claim elements.

Claims (22)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the property described in the following claims is claimed as property.
2. CLAIMS 1. An electrolytic apparatus characterized in that it comprises an electrolytic cell having at least one polymeric electrode filled with carbon. The electrolytic apparatus according to claim 1, characterized in that at least one polymeric electrode filled with carbon comprises electrically conductive carbon disposed in a thermoplastic polymeric binder.
3. 3. The electrolytic apparatus according to claim 2, characterized in that the polymeric binder comprises polyethylene.
4. The electrolytic apparatus according to claim 1, further characterized in that it comprises a body enclosing at least a portion of an electrolytic cell, at least a portion of the body comprising carbon disposed in a polymeric binder.
5. The electrolytic apparatus according to claim 4, characterized in that at least a portion of the body serves at least as an electrode of the electrolytic cell.
6. The electrolytic apparatus according to claim 1, further characterized in that it comprises a source of an electrolyte comprising at least one of a halite and a halide.
7. The electrolytic apparatus according to claim 6, characterized in that the electrolyte comprises a salt of hydrochloric acid.
8. 8. The electrolytic apparatus according to claim 6, characterized in that the electrolyte comprises a chloride.
9. 9. The electrolytic apparatus according to claim 6, characterized in that the electrolyte further comprises at least one oxidizing agent selected from the group consisting of chlorates, perchlorates, hypohalites, permanganates, chromates and peroxides.
10. The electrolytic apparatus according to claim 1, further characterized in that it comprises a source of electric potential connected to at least one polymeric electrode filled with carbon and providing less than about 3 volts to the electrolytic cell.
11. The electrolytic apparatus according to claim 10, further characterized in that it comprises a circuit constructed to regulate the electrical potential in the electrolytic cell by at least about two volts.
12. The electrolytic apparatus according to claim 1, characterized in that at least one polymeric electrode filled with carbon serves as a cathode.
13. The electrolytic apparatus according to claim 1, characterized in that at least one polymeric electrode filled with carbon comprises at least one metallic core.
14. The electrolytic apparatus according to claim 1, characterized in that at least one polymeric electrode filled with carbon comprises an electrocatalytic coating arranged on at least a portion of a surface thereof.
15. 15. A method characterized in that it comprises providing an electrolytic cell having at least one polymer electrode loaded with carbon.
16. 16. The method according to claim 15, further characterized in that it comprises establishing an electric current through at least one polymeric electrode loaded with carbon.
17. 17. The method according to claim 16, characterized in that establishing the electric current comprises providing current with a potential of less than about 3 volts.
18. 18. The method according to claim 17, characterized in that establishing the electric current comprises providing current with a potential of at least about two volts.
19. The method according to claim 16, characterized in that establishing the electric current comprises connecting a terminal of an electrical source to a polymer cathode charged with carbon of the electrolytic cell.
20. 20. The method according to claim 16, characterized in that establishing the electric current further comprises connecting a terminal of an electrical source to a polymeric electrode charged with carbon having an electroactive coating disposed on at least a portion of a surface thereof. The method according to claim 16, characterized in that establishing the electric current comprises connecting an electrical source to a polymeric electrode charged with carbon having a metallic core. The method according to claim 16, characterized in that establishing the electric current comprises conducting the current from the electrical source to a polymeric electrode charged with carbon through an electrically conductive cross-linked member that contacts at least a portion of the polymeric electrode loaded with carbon.