Abstract:
Cells and methods of producing hydrogen and oxygen from an aqueous solution at about 90% of the Faraday Limit are provided. An exemplary method includes the steps of placing a graphite electrode and a nickel electrode in an alkaline solution comprising colloidal silver, colloidal magnesium and a powdered metal such as aluminum, and applying a constant positive voltage to the nickel electrode. Further, the example includes cyclically applying a negative voltage potential to the graphite electrode by turning on the negative applied voltage for a first time period and switching off the negative voltage for a second time period. The second time period should be sufficient to permit removal of substantially all or at least some of any aluminum or zinc deposited on the graphite electrode. Graphite-containing electrodes may be pretreated to infuse with a precious metal.

Description:
STATEMENT OF RELATED APPLICATIONS 
     This application claims priority from U.S. provisional patent application No. 61/107,197 filed Oct. 21, 2008, and from U.S. provisional patent application No. 61/005,961 filed on Dec. 10, 2007. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present technology relates to the field of electrolysis, and more particularly to the use of electrolysis techniques to produce hydrogen and oxygen gasses. 
     2. Description of the Related Art 
     In the field of electrolysis it is generally regarded as highly desirable to be able to produce hydrogen (and oxygen) at or near the Faraday Limit of 10.5873 Joules per ml, which is the power presumed necessary to be 100% efficient. While many systems have been proposed to meet this goal, it appears that electrolysis may often require exotic chemicals and complex electrical switching systems to exceed even a modest 70% of the Faraday Limit. Exceeding this limit of 10.5873 J/ml generally requires replenishing or replacing some consumables, for example, replacing electrodes due to dissolution and/or the replenishing of consumed chemical(s). 
     SUMMARY 
     An exemplary embodiment of an electrolysis cell and process produces hydrogen and oxygen gasses, by electrolysis of water, at efficiencies ranging above about 80% of the Faraday Limit and approaching and often exceeding about 90% of the Faraday Limit. An embodiment of the technology employs a minimum of two electrodes per cell to provide a system that requires little maintenance, such as electrode repair or maintenance of chemicals, other than addition of make up water to compensate for water consumed in the process. Another exemplary embodiment provides an electrolysis system that may use DC power rather than complex alternating current waveforms and fixed non-replaceable elements. 
     An exemplary embodiment provides a method of producing hydrogen and oxygen from an aqueous solution. The method includes the steps of placing a graphite electrode and a nickel electrode in an alkaline electrolyte comprising colloidal silver, colloidal magnesium and aluminum powder, and applying a constant positive voltage to the nickel electrode. Further, the method includes cyclically applying a negative voltage potential to the graphite electrode by turning on the negative applied voltage for a first time period and switching off the negative voltage for a second time period. The second time period should be sufficient to permit removal of substantially all or at least some of any aluminum deposited on the graphite electrode. 
     An exemplary embodiment provides a cell producing hydrogen and oxygen gas from an aqueous solution. The cell includes an alkaline electrolyte having colloidal silver, colloidal magnesium, and a metal powder comprising aluminum powder. It also has at least one positive electrode disposed at least partially in the alkaline solution and at least one switching negative electrode that includes graphite, infused with a precious metal. The switching negative electrode is also disposed at least partially in the electrolyte. In addition, the cell has a first chamber configured and located to capture gas produced at the positive electrode; and a second chamber configured and located to capture gas produced at the at least one switching negative electrode. Further, it includes an automatic controller cyclically applying negative voltage potential to the switching negative electrode according to a predetermined sequence. In an alternate embodiment, the aluminum powder may be substituted with finely divided zinc hydroxide. In this instance, the positive electrode comprises nickel and is pre-treated with zinc, as explained here below 
     An additional exemplary embodiment provides a cell producing hydrogen and oxygen gas from an aqueous electrolyte. The cell includes an alkaline electrolyte comprising colloidal silver, colloidal magnesium, and a metal powder comprising aluminum. The cell has at least one positive electrode disposed at least partially in the alkaline electrolyte; and a plurality of switching negative electrodes. The switching electrodes each comprise graphite, infused with a precious metal, and the plurality of switching negative electrodes is disposed at least partially in the alkaline electrolyte. The cell has a first chamber configured and located to capture gas produced at the positive electrode; and a second chamber configured and located to capture gas produced at the plurality of switching negative electrodes. The cell also includes an automatic controller cyclically applying negative voltage potential to each of the plurality of switching negative electrodes for a predetermined time and according to a predetermined sequence. In an alternate embodiment, the aluminum powder may be substituted with finely divided zinc hydroxide. In this instance, the positive electrode comprises nickel and is pre-treated with zinc, as explained here below 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present technology, and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying schematic, not-to-scale drawings in which: 
         FIG. 1  illustrates an exemplary embodiment that has 1+n switched electrodes; where n=6; 
         FIG. 2  illustrates a schematic of an embodiment of a switching relay; 
         FIG. 3  is a block diagram illustrating features of an exemplary embodiment of a controller; 
         FIG. 4  is a schematic of an exemplary embodiment of a controller showing additional detail; 
         FIG. 5  illustrates an exemplary generalized embodiment of an electrolysis cell; 
         FIGS. 6-7  illustrate exemplary embodiments of electrolysis cells with differing polarities on the electrodes; 
         FIG. 8  illustrates TABLE 1; 
         FIG. 9  is an exemplary embodiment of a solar home power application; and 
         FIG. 10  is an exemplary embodiment of a transportation application. 
     
    
    
     DESCRIPTION 
     In the following description, numerous details may be set forth to provide a thorough understanding of the present technology. However, it will be apparent to those skilled in the art that the present technology may be practiced without these specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present technology in unnecessary detail. For the most part, details considering alternate material choices and design configurations and the like have been omitted inasmuch as details are not necessary to obtain complete understanding of the present technology and are within the skills of persons of ordinary skill in the relevant art. 
     In the appended drawings, depicted features are not necessarily shown to scale. Further, like or similar features are designated by the same reference numeral through the several views, as far as possible. 
       FIG. 1  illustrates an exemplary embodiment of an electrolysis cell  5  that includes a chemical bath  30 , which is cylindrical in this case, but which may be of another geometric configuration, such as square, hexagonal, etc., in cross section. The chemical bath  30  has a central electrode  10  to which is applied a fixed voltage. The central electrode is surrounded by six switched voltage electrodes  20 ,  21 ,  22 ,  23 ,  24 ,  25  in this embodiment, although another number of electrodes may also be used. Each of these electrodes  20 - 25  are subjected to a pulsed or cyclical applied negative voltage. Thus, each switched electrode  20 - 25  may be “on” (voltage applied) or “off” (voltage not applied). Thus, for example, each of switched electrodes  20 - 25  has a connector  60 ,  61 ,  62 ,  63 ,  64 ,  65 , respectively. As shown schematically in  FIG. 2 , a switch relay  90  includes a series of switches  80 - 85 . Each of the switches  80 - 85  is able to close a circuit with a corresponding one of the connectors  60 - 65 . When a switch is closed, a voltage is applied via the closed switch through the connector to the electrode. A constant voltage is applied via line  91  through connector  70  to the central electrode  10 . Thus, the switched electrodes  20 - 25  may be switched on in any pre-determined sequence such that one of the electrodes  20 - 25  is on while the others are off.  FIG. 3  illustrates an example of a controller system  100  that may be used to achieve the switching automatically. Of course, other types of controllers are also useful as long as they can “pulse” the switched electrodes  20 - 25  on and off and maintain a constant voltage at the central electrode  10 . Further, the chemical bath  30  has separate gas chambers  40 ,  50  that are isolated from each other. The gas chamber  50  surrounding an upper portion of central electrode  10  is an oxygen chamber, while the gas chamber surrounding upper portions of the switched electrodes  20 - 25  is a hydrogen chamber. These chambers are used to capture off-gasses from the electrolysis process produced at the electrodes, and the off gasses may be siphoned off from these chambers by conduits (not shown) for any useful purpose. More than two chambers may also be useful, depending upon the configuration of the chemical bath  30 , the number of fixed electrodes  10  per chemical bath  30 , the number of switched electrodes  20 - 25 , and other factors. Chemical bath  30  contains an electrolysis solution  35 , indicated by its upper surface level in  FIG. 1 . 
     A “switching cycle” is the time period between when a switching electrode is first turned on (or off) and when it is next turned on (or off). The switching electrodes are “pulsed” by a pulsing period that is the time period from being turned on to being turned off. Referring to  FIG. 3 , exemplary controller  100  includes a variable timer  110  for setting the switching cycle time. The variable timer  110  is coupled to a decoder  130  through a divider  120 . The decoder  130  sends signals to relay drivers  140 - 145  (shown generically as  140 - 140   n  in  FIG. 3 , for example) that are each in communication with a corresponding relay switch  80 - 85 . The relay switches  80 - 85  are each coupled to a corresponding connector  60 - 65 . As explained above, these connectors  60 - 65  are each in turn connected to a corresponding switched electrode  20 - 25 . 
       FIG. 5  is a schematic illustration of an exemplary and generalized embodiment of an electrolysis system  5  that has a single fixed voltage electrode  10  and n switched voltage electrode(s)  20 ,  20   n . The illustrated embodiment shows a case where “n” equals 2, but of course n may be any integer. The positive electrode  10  is located at or near the center of the chemical bath  30  surrounded by a circular array of n electrodes  20 ,  20   n . These n electrodes  20 ,  20   n  may be in either a negatively charged state or off, as described above. 
     In an exemplary embodiment, the positively charged electrode  10  may be a nickel electrode. Another electrolytically equivalent electrode, such as nickel alloy, Incalloy™, tungsten, tungsten carbide, and the like, may also be useful. An exemplary embodiment of switched electrode element  20  is a proprietary carbon-based electrode that is available from Global Hydrogen, Inc. of Bertram, Tex. The chemical bath  30  utilized with this electrode combination may suitably include finely divided aluminum. 
     In another exemplary embodiment, the switched negative electrodes  20 ,  20   n  may include nickel, or nano nickel, or nano nickel and iron, or tungsten, or tungsten carbide. The positively charged electrode  10  may be graphite. In this embodiment, the chemical bath may contain finely divided zinc hydroxide, instead of aluminum. 
     According to the example of  FIG. 5 , a fixed positive voltage is connected to connection line  91  and a negative voltage is connected to connection line  90 . The fixed electrode  10  is connected directly to the positive voltage connection line  91 . The electrode elements  20 ,  20   n  each include a connector  60 - 60   n , respectively, and these connectors  60 - 60   n  may each be sequentially coupled to the negative voltage connection line  90  through a corresponding relay switch  80 - 80   n.    
     The example of a chemical bath  30  shown in  FIG. 5  includes two isolated gas chambers  40  and  50  to separate H 2 O (liquid), hydrogen (gas) and oxygen (gas). Details of the electrolysis solution  35  in the chemical bath  30  are described below. 
     As used herein, the term “out-gasses” refers to gasses produced in the processes of embodiments including production through electrolysis and production through the reaction of metals with components of the electrolysis liquid. 
     The exemplary embodiment of the system  5  shown in  FIG. 5  is in a quiescent state with all negative electrodes  20 ,  20   n  off. External power may be supplied to electrodes  20 - 20   n  through corresponding relay switches  80 - 80   n  from connection line  90 , and to electrode  10  via line  91 . Electrode elements  20 ,  20   n  are always either (a) at negative voltage potential when switched on or (b) disconnected (or “off”). Electrode element  10  is always positive. However, reverse voltage may be applied with different results. In the quiescent state, all relays  80 ,  80   n  are in the normally open state and no gasses are emitted from either electrode  10  or  20 ,  20   n . Relays  80 ,  80   n  are operated sequentially (i.e. for the configuration in  FIG. 5 , connecting line  90  may rotate). 
     Referring to  FIG. 6 , when relay  80  closes, it applies a (−) negative voltage to electrode  20  and electricity flows between electrode  20  and positive electrode  10  through the electrolytic solution of chemical bath  30 . Electrolysis takes place in the chemical bath  30 , so that oxygen out-gasses at electrode  10  while hydrogen out-gasses at electrode  20 . This gas production continues for a time period that extends beyond the time when the controller  100  relay switch  80  opens (disconnects from electrode  20 ) and closes relay  81  (not shown). The controlled process of timed opening and closing of relays according to a predetermined schedule is repeated sequentially for each electrode from  20  through  20   n , and then the cycle repeats starting at electrode  20 . 
     During the process, electrode  10  continues producing O 2  (gas) as long as the controller is sequencing and any of electrodes  20  through  20   n  produces H 2  (gas) as long as it is live and for a period immediately after applied voltage is removed and it is dead. According to an exemplary embodiment, immediately after any electrode  20   n  is deselected by the controller and is dead, it will continue to produce H 2  (gas) for a period of time, despite being disconnected. After a predetermined period of time, the controller  100  via the relay switching mechanism, for example as described above, switches the applied voltage from one electrode (e.g. electrode  20  (n−1)) to the next electrode (e.g. electrode  20   n ). The process repeats and continues to cycle until it is stopped, when the system returns to the quiescent state. Note that hydrogen is emitted from the (−) electrode and oxygen is emitted from the (+) electrode. 
     Referring to exemplary  FIG. 7 , the polarity of the electrodes is reversed relative to that of  FIG. 6 . For example, in  FIG. 7 , the central electrode  10  is negatively charged while the switched electrodes  20 - 20   n  are positively charged, when activated. 
     Electrode Preparation 
     According to an exemplary embodiment, the system uses two types of electrodes: a metal electrode, desirably nickel or an alloy of nickel, and graphite. These electrodes are treated before being used. It is theorized, without being bound, that the treatment saturates the pores of the electrodes with colloidal material and that it also increases the effective surface area of the electrodes by etching their surfaces. 
     In an exemplary embodiment, a solution that includes colloidal platinum, available from Purest Colloids, Inc. of Westhampton, N.J., USA, may be used in pre-treating the electrodes. The treatment solution may be prepared by adding about 75 ml of colloidal platinum to 75 ml distilled water and 10 ml of 98% sulfuric acid. Of course, for larger batches, these volumes may be increased proportionately. The colloidal metal is not restricted to platinum but may be any colloidal precious metal such as gold, palladium, rhenium, ruthenium, and the like. The electrodes are immersed at least partially in the solution and a positive terminal of a power source may be connected to the nickel electrode and a negative to the graphite electrode. Upon current flow, the graphite electrode becomes impregnated with platinum. This may be carried out, for example, at 4 volts dc and a 5 amp current. Then, after elapse of a time period, typically but not necessarily in the range 10-15 seconds, polarity is reversed, applying the same current and voltage potential, to plate platinum onto the nickel electrode&#39;s surfaces. This reversing of polarity may be carried out several times, desirably while heating the electrolysis solution to about 108° F. The process may be carried out for about 10 minutes, and then the electrodes may be removed and washed in distilled water. 
     An alternative embodiment of a method of electrode treatment includes using a palladium or platinum anode and a graphite or metal cathode to create a metal colloid and carrying out the infusing and plating in one step. 
     Cell Operation 
     As explained above with reference to  FIG. 6 , electrode element  10  has a positive voltage at all times and electrode elements  20 ,  20   n  are always either negative when connected, or otherwise disconnected. In the quiescent state, electrode elements  20 ,  20   n  are disconnected by relays  80 ,  80   n , respectively, and no gas is emitted from electrode elements  10  or  20 ,  20   n . In the active state, the controller  100  closes and opens relays  80 ,  80   n  in a predetermined scheduled sequence around the illustrated circular cell until the process is terminated. When the controller  100  closes relay element  80 , a negative voltage is applied to electrode  20 , for example, while electrode  10  is always positive. While relay  80  is closed, copious amounts of hydrogen are emitted from electrode element  20  and oxygen is emitted from electrode element  10 . Due to electrolysis reactions, metal hydroxide present in the chemical bath solution plates out onto electrode  20  as a metallic coating while the electrolysis generates hydrogen and oxygen. 
     In an exemplary embodiment, the voltage controller  100  is preset or pre-programmed for a “relay closed” time period of three seconds for each electrode  20 ,  20   n . Thus, it automatically closes a relay for each negative electrode sequentially for three seconds. As a consequence, the metal is plated onto the electrode for which the relay is closed (i.e. the “live” negative electrode) for three seconds. When the controller opens the relay, components of the chemical bath  30  solution commence reducing the plated out metal on the now dead electrode, thereby releasing copious hydrogen due to the reduction of metal to metal hydroxide, until substantially all the metal is dissolved back into element  30 , or until a negative voltage potential is again applied to the electrode, when metal plating will recommence. In general, after the negative potential is disconnected from the electrode, the disconnected electrode  20  will continue producing gas at a gradually reducing rate and will substantially return to the quiescent state in about seven seconds. In the illustrated example embodiment shown in  FIG. 1 , there are six electrodes  20  which the controller  100  may sequentially connect to the negative connection lines  90  for three seconds each. Thus, the initial negative electrode  20  produces gas for a minimum of about ten seconds (three seconds while connected and seven seconds after disconnection). The electrode  20  will be selected for re-connection to line  90 , according to the controller sequence, fifteen seconds after it was disconnected. The controller  100  establishes a three-seconds “on” and fifteen-seconds “off” sequence for each electrode  20 ,  20   n . The production rate of this system averages over about 90% of the hydrogen that stoichiometry would predict (see  FIG. 8 , Table 1). 
     The gas-producing electrochemical process (metal plating onto the electrode when it is live and metal converting back to metal hydroxide when the electrode is dead) is believed, without being bound, to be of a catalytic nature and should continue as long as H 2 O lost through conversion to hydrogen and oxygen is replenished. It is believed, without being bound, that the colloidal silver and colloidal magnesium along with palladium infused in the graphite electrode have a catalytic effect. 
     When the controller  100  activates an electrode with an applied negative potential, for example electrode  20 , electrical current will flow through the electrolyte chemical bath solution  30  between positive electrode  10  and negative electrode  20 . Metal is plated on electrode  20 , and if the process is allowed to continue, electrode  20  would become increasingly heavily plated, thus changing its electrical potential. As a result, its rate of hydrogen gas production would decline and finally cease. However, according to embodiments of the present technology, electrode  20  is disconnected (the applied potential is removed) after a predetermined period of time. In the non-limiting example described above, this time period was three seconds, although other longer or shorter time periods may be useful as well. In general, the time period may be selected based on several factors, one of which is to permit sufficient “electrode off” time to permit the chemical bath components to oxidize substantially all or so much of the metal from the electrode surface so that the amount of plated metal does not build up to the point of adversely affecting the rate of hydrogen gas production during the time period that the electrode is on. Thus, the chemicals in the electrolyte  35  may begin reacting with the metal deposited on electrode  20 , thereby releasing more gas, and may substantially completely remove the deposited metal by the time electrode  20  is again selected by the controller  100  for activation. The total amount of gasses produced includes both (a) gas produced while an electrode is live and (b) gas produced when the electrode is dead. Accordingly, the electrical energy input needed to produce the total amount of gasses is less than would be the case if the gas produced under condition (b) also required energy (electricity) input. 
     The cycle time of the controller  100  may be set or pre-programmed to take into account various factors, including, but not limited to, power supplied to the electrodes, the voltage, the current, the electrode active surface area, the number of cells (a cell includes a negative electrode, the positive electrode and the chemical bath solution), and the cell configuration. 
     The Controller 
     It is understood that the illustrated exemplary embodiment of controller  100  in  FIGS. 3 and 4  is merely one of many potentially useful controllers provided for explanatory purposes. Other forms of electronic controllers, such as Asics, or software controlled devices or micro-processors may be substituted, for example. 
     A more detailed drawing of an embodiment of an exemplary controller  100  is shown in  FIG. 4 . For purposes of description, element  110  may be a variable LM324 Op Amp oscillator generating square waves controlled by the RC time constant of R 1 , R 16  and C 11 . Element  110  may, for example, be adjusted for a three-minute output of Divider Q 5 . Divider  120  may be a seven stage CMOS Divider. Since the exemplary circuit has six switched elements  20 - 20   n , a four bit divider would suffice. The unused stages Q 1 -Q 4  buffer the clock for more accurate timing, if required. The outputs Q 5 -Q 7  are input to an analog sixteen bit decoder  130 . A digital decoder may also be used. The decoder drives a Bipolar NPN transistor(s) MOSFET substitutable and has an LED to indicate which element is selected. Output X 6   130  returns the counter to reset, causing the divider  120  to reset starting the count over after every sixth count. The number of counts are thus=n, up to n=8 for this example of a chip, or n=16 by using additional logic or a 4:16 bit decoder. The base input of the transistors  140 - 140   n  are normally disconnected and grounded turning the transistor(s) “OFF.” When the counter  120  selects the channel on Output X 6   130 , a positive voltage is applied to the selected transistor turning the selected coil on. Coils  80 - 80   n  apply voltage on line  90  to the appropriate electrode. A diode is used to suppress high voltage induced by switching of the coils. 
     The controller system  100  shown in  FIGS. 3 and 4  operates the relays  80 ,  80   n  at precise predetermined times. A first LED (D 2 ), which may be any color, such as red, pulses at the Adjusted Oscillator frequency and a second LED (D 7 ), which may be any color (conveniently a different color from the first LED), pulses at the electrode timing frequency, which, in this example, is three seconds “live.” Of course, timing can be set by monitoring the state changes of the LEDs (D 8 -D 13 ). 
     There are potentially a wide range of applications for the present technology. For example,  FIG. 9  illustrates a residential application and  FIG. 10  illustrates an automotive application. Other applications may become apparent to one of skill in the art who has read this disclosure. From the foregoing disclosure, it will be appreciated by those skilled in the art that the techniques described herein may be applied to a wide variety of systems for the production of hydrogen and oxygen that utilizes a system of electrolysis and chemical reduction. 
     The following examples merely illustrate aspects of the technology and are not limiting of the invention which is defined by the claims here below. 
     EXAMPLES 
     Hydrogen Production with Aluminum Powder 
     A chemical bath was prepared with a solution that included the following solutes: 
     50-ml colloidal silver 
     50 ml colloidal magnesium 
     50 ml distilled water 
     20 grams sodium hydroxide 
     20 grams potassium hydroxide 
     7 grams of aluminum 
     This solution  35  was placed in a 250 ml beaker  30 . To this, 7 grams of aluminum were added and allowed to digest before the electrodes  10 ,  20  were inserted. The power supply was connected to the switching circuit, with the output voltage set at 2.0 volts DC (see  FIG. 8 , Table 1, Col. 1) at 0.25 amps (see Table 1, Col. 2). The positive wire  70  was connected to the nickel electrode  10  and negative lead  60  to the graphite electrodes  20 . During the hydrogen/oxygen production, the aluminum hydroxide was reduced to aluminum on the graphite electrode and the aluminum reacted with the strong base electrolyte, thereby producing hydrogen on the graphite electrodes. Oxygen was produced on the nickel electrode as a result of the metal reduction. The gas flow was tested for the presence of hydrogen and oxygen by piping it through soapy water and then lighting the bubbles, which exploded very loudly, strongly indicating the presence of both hydrogen and oxygen. 
     It should also be appreciated that the illustrated exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof. 
     Hydrogen Production with Zinc 
     A chemical bath was prepared with a solution that included the following solutes: 
     50-ml colloidal silver 
     50 ml colloidal magnesium 
     50 ml distilled water 
     20 grams sodium hydroxide 
     20 grams potassium hydroxide 
     7 grams of zinc 
     This solution is placed in a 250 ml beaker  30  to pre-treat a nickel electrode. To this, 7 grams of zinc are connected to a nickel electrode and allowed to digest, depositing zinc onto the nickel. The nickel electrode is then removed. The power supply is connected to the switching circuit, with the output voltage set at 2.0 volts DC, as in the above example. The positive wire is connected to the graphite electrode and negative lead to the pre-treated nickel electrode. During the hydrogen/oxygen production, the zinc hydroxide is reduced to zinc on the nickel electrode and the zinc reacts with the nickel in the strong base electrolyte, thereby producing hydrogen on the nickel electrodes. Oxygen is produced on the graphite electrode as a result of the metal reduction. The gas flow is tested for the presence of hydrogen and oxygen by piping it through soapy water and then lighting the bubbles, which explode very loudly, strongly indicating the presence of both hydrogen and oxygen.