Multi-cell dual voltage electrolysis apparatus and method of using same

Abstract

A method and apparatus for achieving high output efficiency from an electrolysis system (100) using a plurality of electrolysis cells all located within a single electrolysis tank (101) is provided. Each individual electrolysis cell includes a membrane (105-107), a plurality of low voltage electrodes comprised of at least a first and second anode (117/118; 125/126) and at least a first and second cathode (121/122; 129/130), and a plurality of high voltage electrodes comprised of at least an anode (119; 127) and a cathode (123; 131). Within each cell, the high voltage anode is interposed between the first and second low voltage anodes and the high voltage cathode is interposed between the first and second low voltage cathodes. The low voltage applied to the low voltage electrodes and the high voltage applied to the high voltage electrodes is pulsed with the pulses occurring simultaneously.

Description

CROSS-REFERENCE TO RELATED APPLICATION

Under 35 U.S.C. 119, the present application claims the benefit of the earlier filing date and the right of priority to Canadian Patent Application Serial No. 2,590,487, filed May 30, 2007, the disclosure of which is hereby incorporated by reference for any and all purposes.

FIELD OF THE INVENTION

The present invention relates generally to electrolysis systems and, more particularly, to a high efficiency electrolysis system and methods of using same.

BACKGROUND OF THE INVENTION

Fossil fuels, in particular oil, coal and natural gas, represent the primary sources of energy in today's world. Unfortunately in a world of rapidly increasing energy needs, dependence on any energy source of finite size and limited regional availability has dire consequences for the world's economy. In particular, as a country's need for energy increases, so does its vulnerability to disruption in the supply of that energy. Additionally, as fossil fuels are the largest single source of carbon dioxide emissions, a greenhouse gas, continued reliance on such fuels can be expected to lead to continued global warming. Accordingly it is imperative that alternative, clean and renewable energy sources be developed that can replace fossil fuels.

Hydrogen-based fuel is currently one of the leading contenders to replace fossil fuel. There are a number of techniques that can be used to produce hydrogen, although the primary technique is by steam reforming natural gas. In this process thermal energy is used to react natural gas with steam, creating hydrogen and carbon dioxide. This process is well developed, but due to its reliance on fossil fuels and the release of carbon dioxide during production, it does not alleviate the need for fossil fuels nor does it lower the environmental impact of its use over that of traditional fossil fuels. Other, less developed hydrogen producing techniques include (i) biomass fermentation in which methane fermentation of high moisture content biomass creates fuel gas, a small portion of which is hydrogen; (ii) biological water splitting in which certain photosynthetic microbes produce hydrogen from water during their metabolic activities; (iii) photoelectrochemical processes using either soluble metal complexes as a catalyst or semiconducting electrodes in a photochemical cell; (iv) thermochemical water splitting using chemicals such as bromine or iodine, assisted by heat, to split water molecules; (v) thermolysis in which concentrated solar energy is used to generate temperatures high enough to split methane into hydrogen and carbon; and (vi) electrolysis.

Electrolysis as a means of producing hydrogen has been known and used for over 80 years. In general, electrolysis of water uses two electrodes separated by an ion conducting electrolyte. During the process hydrogen is produced at the cathode and oxygen is produced at the anode, the two reaction areas separated by an ion conducting diaphragm. Electricity is required to drive the process. An alternative to conventional electrolysis is high temperature electrolysis, also known as steam electrolysis. This process uses heat, for example produced by a solar concentrator, as a portion of the energy required to cause the needed reaction. Although lowering the electrical consumption of the process is desirable, this process has proven difficult to implement due to the tendency of the hydrogen and oxygen to recombine at the technique's high operating temperatures.

A high temperature heat source, for example a geothermal source, can also be used as a replacement for fossil fuel. In such systems the heat source raises the temperature of water sufficiently to produce steam, the steam driving a turbine generator which, in turn, produces electricity. Alternately the heat source can raise the temperature of a liquid that has a lower boiling temperature than water, such as isopentane, which can also be used to drive a turbine generator. Alternately the heat source can be used as a fossil fuel replacement for non-electrical applications, such as heating buildings.

Although a variety of alternatives to fossil fuels in addition to hydrogen and geothermal sources have been devised, to date none of them have proven acceptable for a variety of reasons ranging from cost to environmental impact to availability. Accordingly, what is needed is a new energy source, or a more efficient form of a current alternative energy source, that can effectively replace fossil fuels without requiring an overly complex distribution system. The present invention provides such a system and method of use.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for achieving high output efficiency from an electrolysis system using a plurality of electrolysis cells all located within a single electrolysis tank. Each individual electrolysis cell includes a membrane which separates the portion of the electrolysis tank containing that electrolysis cell into two regions. Additionally, each electrolysis cell includes a plurality of low voltage electrodes and a plurality of high voltage electrodes. The plurality of low voltage electrodes includes at least a first and second low voltage anode contained within the first region of the electrolysis cell and at least a first and second low voltage cathode contained within the second region of the electrolysis cell. The plurality of high voltage electrodes includes at least a first high voltage anode contained within the first region of the electrolysis cell and interposed between the first and second low voltage anodes, and a first high voltage cathode contained within the second region of the electrolysis cell and interposed between the first and second low voltage cathodes. The low voltage applied to the low voltage electrodes is pulsed as is the high voltage applied to the high voltage electrodes, the low voltage pulses and the high voltage pulses being timed to occur simultaneously.

Preferably the low and high voltage pulses occur at a frequency between 50 Hz and 1 MHz, and more preferably at a frequency of between 100 Hz and 10 kHz. The pulse duration is preferably between 0.01 and 75 percent of the time period defined by the frequency, and more preferably between 1 and 50 percent of the time period defined by the frequency. Preferably the ratio of the high voltage to the low voltage is at least 5:1, more preferably within the range of 5:1 to 100:1, still more preferably within the range of 5:1 to 33:1, and still more preferably within the range of 5:1 to 20:1. Preferably the low voltage is between 3 and 1500 volts, more preferably between 12 and 750 volts. Preferably the high voltage is between 50 volts and 50 kilovolts, more preferably between 100 volts and 5 kilovolts.

Preferably the liquid within the tank is comprised of one or more of; water, deuterated water, tritiated water, semiheavy water, heavy oxygen water, and/or any other water containing an isotope of either hydrogen or oxygen. Preferably the liquid within the electrolysis tank includes an electrolyte with a concentration in the range of 0.05 to 10 percent by weight, more preferably in the range of 0.05 to 2.0 percent by weight, and still more preferably in the range of 0.1 to 0.5 percent by weight.

The electrodes can be fabricated from a variety of materials, although preferably the material for each electrode is selected from the group consisting of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys thereof.

In at least one embodiment, the electrolysis system is cooled. Cooling is preferably achieved by thermally coupling at least a portion of the electrolysis system to a portion of a conduit containing a heat transfer medium. The conduit can surround the electrolysis tank, be integrated within the walls of the electrolysis tank, or be contained within the electrolysis tank.

In at least one embodiment, the electrolysis system also contains a system controller. The system controller can be used to perform system optimization, either during an initial optimization period or repeatedly throughout system operation.

A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of an exemplary embodiment of the invention utilizing a three cell configuration;

FIG. 2 is an illustration of an alternate embodiment based on the configuration shown in FIG. 1 utilizing multiple sets of low voltage electrodes for each cell;

FIG. 3 is an illustration of an alternate embodiment based on the configuration shown in FIG. 1 utilizing multiple sets of high voltage electrodes for each cell;

FIG. 4 is an illustration of an alternate embodiment based on the configuration shown in FIG. 1 utilizing multiple sets of low voltage electrodes and multiple sets of high voltage electrodes for each cell;

FIG. 5 is an illustration of an alternate embodiment utilizing a cylindrically-shaped tank;

FIG. 6 is an illustration of an alternate embodiment based on the configuration shown in FIG. 1 utilizing switching power supplies;

FIG. 7 is an illustration of an alternate embodiment based on the configuration shown in FIG. 1 utilizing switching power supplies with internal pulse generators and a system controller;

FIG. 8 is an illustration of one mode of operation;

FIG. 9 is an illustration of an alternate mode of operation that includes initial process optimization steps;

FIG. 10 is an illustration of an alternate, and preferred, mode of operation in which the process undergoes continuous optimization;

FIG. 11 is an illustration of an alternate embodiment of FIG. 1 utilizing multiple low voltage supplies and multiple high voltage supplies; and

FIG. 12 is an illustration of an alternate embodiment of FIG. 1 that includes a system controller.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

FIG. 1 is an illustration of an exemplary, and preferred, embodiment of the invention which can be used, for example, as a heat generator. Electrolysis system 100 includes a tank 101 comprised of a non-conductive material, the size of the tank depending primarily upon the desired output level for the system, for example the desired heat production. Although tank 101 is shown as having a rectangular shape, it will be appreciated that the invention is not so limited and that tank 101 can utilize other shapes, for example cylindrical, square, irregularly-shaped, etc. Tank 101 is substantially filled with liquid 103. In at least one preferred embodiment, liquid 103 is comprised of water with an electrolyte, the electrolyte being either an acid electrolyte or a base electrolyte. Exemplary electrolytes include potassium hydroxide and sodium hydroxide. The term “water” as used herein refers to water (H₂O), deuterated water (deuterium oxide or D₂O), tritiated water (tritium oxide or T₂O), semiheavy water (HDO), heavy oxygen water (H₂¹⁸O or H₂¹⁷O) or any other water containing an isotope of either hydrogen or oxygen, either singly or in any combination thereof (for example, a combination of H₂O and D₂O).

A typical electrolysis system used to decompose water into hydrogen and oxygen gases utilizes relatively high concentrations of electrolyte. The present invention, however, has been found to work best with relatively low electrolyte concentrations, thereby maintaining a relatively high initial water resistivity. Preferably the water resistivity prior to the addition of an electrolyte is on the order of 1 to 28 megohms. Preferably the concentration of electrolyte is in the range of 0.05 percent to 10 percent by weight, more preferably the concentration of electrolyte is in the range of 0.05 percent to 2.0 percent by weight, and still more preferably the concentration of electrolyte is in the range of 0.1 percent to 0.5 percent by weight.

The electrolysis system of the invention uses two types of electrodes, one comprised of low voltage electrodes and the other comprised of high voltage electrodes. The system of the invention also includes multiple electrolysis cells, an electrolysis cell defined herein as having at least two low voltage cathodes, at least two low voltage anodes, at least one high voltage cathode interposed between the two low voltage cathodes and at least one high voltage anode interposed between the two low voltage anodes. Furthermore the cathode electrodes (low and high voltage) and the anode electrodes (low and high voltage) within each cell are separated by a membrane, specifically membranes 105-107 in the illustrated embodiment. Accordingly the embodiment illustrated in FIG. 1 includes three electrolysis cells. It should be understood that the invention is not limited to an electrolysis system with a specific number of cells, rather the number of cells depends primarily on the desired output level (e.g., heat production) and the size of the electrolysis tank.

Membranes 105-107 permit ion/electron exchange between the two regions of each cell while keeping separate the oxygen and hydrogen bubbles produced during electrolysis. Maintaining separate hydrogen and oxygen gas regions is important as a means of minimizing the risk of explosions due to the inadvertent recombination of the two gases. Additionally, separating the regions allows the collection of pure hydrogen gas and pure oxygen gas. Accordingly similar polarity electrodes are grouped together with the membranes keeping groups separate. Thus in the exemplary embodiment shown in FIG. 1, only anodes are positioned between membrane 105 and the left side of electrolysis tank 101; only cathodes are positioned between membranes 105 and 106; only anodes are positioned between membranes 106 and 107; and only cathodes are positioned between membrane 107 and the right side of electrolysis tank 101. Exemplary membrane materials include, but are not limited to, polypropylene, tetrafluoroethylene, asbestos, etc.

As noted herein, the present system is capable of generating considerable heat. Accordingly, system components such as the electrolysis tank (e.g., tank 101) and the membranes (e.g., membranes 105-107) that are expected to be subjected to the heat generated by the system must be fabricated from suitable materials and designed to indefinitely accommodate the intended operating temperatures as well as the internal tank pressure. For example, in at least one preferred embodiment the system is designed to operate at a temperature of approximately 90° C. at standard pressure. In an alternate exemplary embodiment, the system is designed to operate at elevated temperatures (e.g., 100° C. to 150° C.) and at sufficient pressure to prevent boiling of liquid 103. In yet another alternate exemplary embodiment, the system is designed to operate at even higher temperatures (e.g., 200° C. to 350° C.) and higher pressures (e.g., sufficient to prevent boiling). Accordingly, it will be understood that the choice of materials (e.g., for tank 101 and membranes 105-107) and the design of the system (e.g., tank wall thicknesses, fittings, etc.) will vary, depending upon the intended system operational parameters, primarily temperature and pressure.

Other standard features of the electrolysis tank are gas outlets for any hydrogen and oxygen gases generated within the tank. In the exemplary embodiment shown in FIG. 1, the oxygen gas produced at the anodes will exit tank 101 at gas outlets 108-109 while hydrogen gas produced at the cathodes will exit the tank at gas outlets 110-111. Replenishment of liquid 103 is preferably through a separate conduit, for example conduit 113. In at least one embodiment of the invention, another conduit 115 is used to remove liquid 103 from the system. Alternately, each cell can include one or more conduits for liquid 103 replenishment. If desired, a single conduit can be used for both liquid removal and replenishment. It will be appreciated that the system can either be periodically refilled or liquid 103 can be continuously added at a very slow rate during system operation.

In the embodiment illustrated in FIG. 1, each cell includes four low voltage electrodes (i.e., two cathodes and two anodes) and two high voltage electrodes (i.e., one cathode and one anode). In the illustrated embodiment, the first cell includes low voltage anodes 117/118 and interposed high voltage anode 119, and includes low voltage cathodes 121/122 and high voltage cathode 123. Noting that adjacent cells preferably co-use sets of electrodes as shown, the second cell includes low voltage cathodes 121/122 and high voltage cathode 123, and includes low voltage anodes 125/126 and interposed high voltage anode 127. The third cell includes low voltage anodes 125/126 and interposed high voltage anode 127, and includes low voltage cathodes 129/130 and high voltage cathode 131.

In FIG. 1, low voltage power source 133 supplies power to all of the low voltage electrodes and high voltage power source 135 supplies power to all of the high voltage electrodes. As described and illustrated, voltage source 133 is referred to and labeled as a ‘low’ voltage source not because of the absolute voltage produced by the source, but because the output of voltage source 133 is maintained at a lower output voltage than the output of voltage source 135.

Preferably and as shown, the faces of the individual electrodes are parallel to one another. It should be understood, however, that the faces of the electrodes do not have to be parallel to one another.

In a preferred embodiment, all of the electrodes are comprised of titanium. In another preferred embodiment, all of the electrodes are comprised of stainless steel. It should be appreciated, however, that other materials can be used and that the same material does not have to be used for both the low voltage and the high voltage electrodes, nor does the same material have to be used for both the low voltage anodes and the low voltage cathodes, nor does the same material have to be used for both the high voltage anodes and the high voltage cathodes. In addition to titanium and stainless steel, other exemplary materials that can be used for the low voltage electrodes and the high voltage electrodes include, but are not limited to, copper, iron, stainless steel, cobalt, manganese, zinc, nickel, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys of these materials. As used in the present specification, a metal hydride refers to any compound of a metal and hydrogen or an isotope of hydrogen (e.g., deuterium, tritium).

Preferably the surface area of each of the faces of the low voltage electrodes (i.e., electrodes 117, 118, 121, 122, 125, 126, 129 and 130 in FIG. 1) is a large percentage of the cross-sectional area of tank 101, typically on the order of at least 40 percent of the cross-sectional area of tank 101, and often between approximately 70 percent and 90 percent of the cross-sectional area of tank 101. The high voltage electrodes may be larger, smaller or the same size as the low voltage electrodes. Although the separation distance between electrodes is dependent upon a variety of factors (e.g., tank size, voltage/current, etc.), in at least one preferred embodiment the separation between the closest low voltage electrodes positioned on either side of a membrane (e.g., in FIG. 1 electrodes 118/121, electrodes 122/125 and electrodes 126/129) is between 0.2 millimeters and 15 centimeters.

Preferably the ratio of the high voltage to the low voltage applied to the high voltage and low voltage electrodes, respectively, is at least 5:1, more preferably the ratio is between 5:1 and 100:1, still more preferably the ratio is between 5:1 and 33:1, and even still more preferably the ratio is between 5:1 and 20:1. Preferably the high voltage generated by source 135 is within the range of 50 volts to 50 kilovolts, and more preferably within the range of 100 volts to 5 kilovolts. Preferably the low voltage generated by source 133 is within the range of 3 volts to 1500 volts, and more preferably within the range of 12 volts to 750 volts.

Rather than continually apply voltage to the electrodes, sources 133 and 135 are pulsed, preferably at a frequency between 50 Hz and 1 MHz, and more preferably at a frequency of between 100 Hz and 10 kHz. The pulse width (i.e., pulse duration) is preferably between 0.01 and 75 percent of the time period defined by the frequency, and more preferably between 1 and 50 percent of the time period defined by the frequency. Thus, for example, for a frequency of 150 Hz, the pulse duration is preferably in the range of 0.67 microseconds to 5 milliseconds, and more preferably in the range of 66.7 microseconds to 3.3 milliseconds. Alternately, for example, for a frequency of 1 kHz, the pulse duration is preferably in the range of 0.1 microseconds to 0.75 milliseconds, and more preferably in the range of 10 microseconds to 0.5 milliseconds. Additionally, the voltage pulses are applied simultaneously to the high voltage and low voltage electrodes via sources 135 and 133, respectively. In other words, in the embodiment illustrated in FIG. 1, the voltage pulses applied to high voltage electrodes 119/123/127/131 coincide with the pulses applied to low voltage electrodes 117/118/121/122/125/126/129/130. Although voltage sources 133 and 135 can include internal means for pulsing the respective outputs from each source, preferably an external pulse generator 137 controls a pair of switches, i.e., a low voltage switch 139 and a high voltage switch 141 which, in turn, control the output of voltage sources 133 and 135 as shown, and as described above. Other means for pulsing the voltage sources are clearly envisioned, for example using switching power supplies coupled to an external pulse generator or using switching power supplies with internal pulse generators. If multiple pulse generators are used, for example one pulse generator coupled to the low voltage source and a second pulse generator coupled to the high voltage source, preferably means such as a system controller are used to insure that the pulses generated by the individual pulse generators are simultaneous.

As previously noted, the electrolysis process of the invention generates considerable heat. To withdraw that heat so that it can be used, and to prevent the liquid within the tank from becoming too hot and boiling at a given temperature, and to prevent possible damage to those system components that may be susceptible to damage, in the preferred embodiments of the invention the system includes means to actively cool the system to within an acceptable temperature range. For example, in at least one preferred embodiment the cooling system does not allow the temperature to exceed 90° C. Although it will be appreciated that the invention is not limited to a specific type of cooling system or a specific implementation of the cooling system, in at least one embodiment the electrolysis tank is surrounded by a coolant conduit 143, portions of which are shown in FIGS. 1-7, 11 and 12. Within coolant conduit 143 is a heat transfer medium, for example water. Coolant conduit 143 can either surround a portion of the electrolysis tank as shown, or be contained within the electrolysis tank, or be integrated within the walls of the electrolysis tank. The coolant pump and heat withdrawal system is not shown in the figures as cooling systems are well known by those of skill in the art.

As will be appreciated by those of skill in the art, there are numerous minor variations of the system described herein and shown in FIG. 1 that will function in substantially the same manner as the disclosed system. As previously noted, alternate configurations can utilize fewer or greater numbers of cells, differently sized/shaped tanks, different electrolytic solutions, and a variety of different electrode configurations and materials. Additionally the system can utilize a range of input powers, frequencies and pulse widths (i.e., pulse duration). In general, the exact configuration depends upon the desired output level as well as available space and power. FIGS. 2-5 illustrate a few alternate configurations, including the use of multiple sets of low voltage electrodes for each cell (e.g., FIG. 2), multiple sets of high voltage electrodes for each cell (e.g., FIG. 3), multiple sets of low voltage and high voltage electrodes for each cell (e.g., FIG. 4), and a horizontal cylindrical tank (e.g., FIG. 5).

FIG. 2 illustrates an alternate embodiment of the system shown in FIG. 1, the alternate configuration replacing low voltage electrode 117 with three low voltage electrodes 201-203, replacing low voltage electrode 118 with three low voltage electrodes 205-207, replacing low voltage electrode 121 with three low voltage electrodes 209-211, replacing low voltage electrode 122 with three low voltage electrodes 213-215, replacing low voltage electrode 125 with three low voltage electrodes 217-219, replacing low voltage electrode 126 with three low voltage electrodes 221-223, replacing low voltage electrode 129 with three low voltage electrodes 225-227, and replacing low voltage electrode 130 with three low voltage electrodes 229-231.

FIG. 3 illustrates an alternate embodiment of the system shown in FIG. 1, the alternate configuration replacing high voltage electrode 119 with two high voltage electrodes 301-302, replacing high voltage electrode 123 with two high voltage electrodes 303-304, replacing high voltage electrode 127 with two high voltage electrodes 305-306, and replacing high voltage electrode 131 with two high voltage electrodes 307-308.

FIG. 4 illustrates an alternate embodiment of the system shown in FIG. 1, the alternate embodiment utilizing the low voltage configuration shown in FIG. 2 and the high voltage configuration shown in FIG. 3.

FIG. 5 illustrates an alternate embodiment of the system shown in FIG. 1, the alternate configuration replacing tank 101 with a horizontally configured cylindrical tank 501, replacing membrane 105 with an appropriately shaped membrane 503, replacing membrane 106 with an appropriately shaped membrane 504, replacing membrane 107 with an appropriately shaped membrane 505, replacing low voltage electrode 117 with disc-shaped low voltage electrode 507, replacing low voltage electrode 118 with disc-shaped low voltage electrode 508, replacing high voltage electrode 119 with disc-shaped high voltage electrode 509, replacing low voltage electrode 121 with disc-shaped low voltage electrode 511, replacing low voltage electrode 122 with disc-shaped low voltage electrode 512, replacing high voltage electrode 123 with disc-shaped high voltage electrode 513, replacing low voltage electrode 125 with disc-shaped low voltage electrode 515, replacing low voltage electrode 126 with disc-shaped low voltage electrode 516, replacing high voltage electrode 127 with disc-shaped high voltage electrode 517, replacing low voltage electrode 129 with disc-shaped low voltage electrode 519, replacing low voltage electrode 130 with disc-shaped low voltage electrode 520, and replacing high voltage electrode 131 with disc-shaped high voltage electrode 521.

It will be appreciated that the supply electronics (i.e., low/high voltage supplies, low/high voltage switches, pulse generator) shown in FIGS. 1-5 represent only one exemplary configuration and that other configurations can be used to supply the requisite pulsed and timed power to the low voltage and high voltage electrodes within the cells of the electrolysis system of the invention. FIGS. 6 and 7 illustrate two additional alternate, and exemplary, configurations. Specifically, FIG. 6 illustrates a system similar to that shown in FIG. 1, except that low voltage supply 133 and low voltage switch 139 are combined into a single low voltage switching power supply 601. Similarly high voltage supply 135 and high voltage switch 141 are combined into a single high voltage switching power supply 603. The embodiment illustrated in FIG. 7 combines the pulse generation within the power supplies, i.e., low voltage supply 701 and high voltage supply 703, and then uses a system controller 705 to coordinate the low voltage pulses and the high voltage pulses produced by the two systems.

It should be understood that the electrolysis system of the present invention can be operated in a number of modes, the primary differences between modes being the degree of process optimization used during operation. For example, FIG. 8 illustrates one method of operation requiring minimal optimization. As illustrated, initially the electrolysis tank, e.g., tank 101, is filled with water (step 801). Preferably the level of water in the tank at least covers the top of the electrodes. The electrolyte can either be mixed into the water prior to filling the tank or after the tank is filled. The frequency of the pulse generator is then set (step 803) as well as the pulse duration (step 805). The initial voltage settings for the low voltage power supply and the high voltage power supply are also set (step 807). It will be appreciated that the order of set-up is clearly not critical to the electrolysis process. Typically, prior to the initiation of electrolysis, the temperature of the water is at room temperature.

Once set-up is complete, electrolysis is initiated (step 809). During the electrolysis process (step 811), and as previously noted, the water is heated by the process itself. Eventually, when operation is no longer desirable, the electrolysis process is suspended (step 813). If desired, prior to further operation the tank can be drained (step 815) and refilled (step 817). Prior to refilling the tank, a series of optional steps can be performed. For example, the tank can be washed out (optional step 819) and the electrodes can be cleaned, for example to remove oxides, by washing the electrodes with diluted acids (optional step 821). Spent, or used up, electrodes can also be replaced prior to refilling (optional step 823). After cleaning the system and/or replacing electrodes as deemed necessary, and refilling the system, the system is ready to reinitiate the electrolysis process.

The above sequence of processing steps works best once the operational parameters have been optimized for a specific system configuration since the system configuration will impact the heat generation efficiency of the process. Exemplary system configuration parameters that affect the optimal electrolysis settings include tank size, quantity of water, type and/or quality of water, electrolyte composition, electrolyte concentration, electrode size, electrode composition, electrode shape, electrode configuration, electrode separation, cell number, cell separation, initial water temperature, low voltage setting, high voltage setting, pulse frequency and pulse duration.

FIG. 9 illustrates an alternate procedure, one in which the process undergoes optimization. Initially the tank is filled (step 901) and initial settings for pulse frequency (step 903), pulse duration (step 905), high voltage supply output (step 907) and low voltage supply output (step 909) are made. Typically the initial settings are based on previous settings that have been optimized for a similarly configured system. For example, assuming that the new configuration was the same as a previous configuration except for the composition of the electrodes, a reasonable initial set-up would be the optimized set-up from the previous configuration.

After the initial set-up is completed, electrolysis is initiated (step 911) and system output is monitored (step 913), for example absolute temperature or the rate of temperature increase. Although system optimization can begin immediately, preferably the system is allowed to run for an initial period of time (step 915) prior to optimization. The initial period of operation can be based on achieving a predetermined output, for example a specific level of temperature increase, or achieving a steady state output (e.g., steady state temperature). Alternately the initial period of time can simply be a predetermined time period, for example 6 hours.

After the initial time period is exceeded, the system output (e.g., temperature rate increase, steady state temperature, etc.) is monitored (step 917) while optimizing one or more of the operational parameters. Although the order of parameter optimization is not critical, in at least one preferred embodiment the first parameter to be optimized is pulse duration (step 919). Then the pulse frequency is optimized (step 920), followed by optimization of the low voltage (step 921) and the high voltage (step 922). In this embodiment after optimization is complete the electrolysis process is allowed to continue (step 923) without further optimization until the process is halted, step 925. In another, and preferred, alternative approach illustrated in FIG. 10, one or more of optimization steps 919-922 are performed continuously throughout the electrolysis process until electrolysis is suspended.

Note that the optimization processes described relative to FIGS. 9 and 10 assume that (i) the cells physical geometry is fixed and (ii) there is no control over the low and/or high voltage applied to individual cell electrodes. If the system does include means for adjusting the physical geometry of the individual cells during electrolysis, for example the spacing between the electrodes within the cells or the cell-to-cell spacing, these parameters can also be altered to further optimize the electrolysis process during system operation. The system can also be configured to provide additional control over the low and/or high voltage applied to the cells. For example, the system shown in FIG. 11 uses a pair of low voltage power supplies 1101/1102 and associated low voltage switches 1103/1104, and a pair of high voltage power supplies 1105/1106 and associated high voltage switches 1107/1108. Systems such as these, although more complex, provide further control and therefore potentially greater optimization.

The optimization process described relative to FIGS. 9 and 10 can be performed manually. In the preferred embodiment, however, the system or portions of the system are controlled via a system controller such as controller 1201 shown in an alternate embodiment of the configuration illustrated in FIG. 1 (i.e., FIG. 12). Assuming that controller 1201 is used to control and optimize the pulse frequency, pulse duration, high voltage and low voltage, system controller 1201 is coupled to the pulse generator and the voltage supplies as shown. If the system controller is only used to control and optimize a subset of these parameters, the system controller is coupled accordingly (i.e., coupled to the pulse generator to control pulse frequency and duration; coupled to the high voltage source to control the high voltage; coupled to the low voltage source to control the low voltage). In order to allow optimization automation, system controller 1201 is also coupled to a system monitor, for example one or more temperature monitors (e.g., monitor 1203). In at least one preferred embodiment system controller 1201 is also coupled to a monitor 1205, monitor 1205 providing either the pH or the resistivity of liquid 103 within electrolysis tank 101, thereby providing means for determining when additional electrolyte needs to be added. In at least one preferred embodiment system controller 1201 is also coupled to a liquid level monitor 1207, thereby providing means for determining when additional water needs to be added to the electrolysis tank. Preferably system controller 1201 is also coupled to one or more flow valves 1209 which allow water, electrolyte, or a combination of water and electrolyte to be automatically added to the electrolysis system in response to pH/resistivity data provided by monitor 1205 (i.e., when the monitored pH/resistivity falls outside of a preset range) and/or liquid level data provided by monitor 1207 (i.e., when the monitored liquid level falls below a preset value).

As will be understood by those familiar with the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosures and descriptions herein are intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims.

Claims

1. An electrolysis system comprising:

an electrolysis tank;

a plurality of electrolysis cells within said electrolysis tank, each of said plurality of electrolysis cells comprising: a membrane dividing said electrolysis cell into a first region and a second region, wherein said membrane permits ion and electron exchange between said first and second regions; a plurality of low voltage electrodes, said plurality of low voltage electrodes comprised of at least a first low voltage anode and at least a second low voltage anode contained within said first region, and said plurality of low voltage electrodes comprised of at least a first low voltage cathode and at least a second low voltage cathode contained within said second region; and a plurality of high voltage electrodes, said plurality of high voltage electrodes comprised of at least a first high voltage anode contained within said first region and interposed between said first low voltage anode and said second low voltage anode, and said plurality of high voltage electrodes comprised of at least a first high voltage cathode contained within said second region and interposed between said first low voltage cathode and said second low voltage cathode;

a low voltage source with a first output voltage electrically connected to said plurality of low voltage electrodes of each electrolysis cell;

a high voltage source with a second output voltage electrically connected to said plurality of high voltage electrodes of each electrolysis cell, wherein said second output voltage is higher than said first output voltage; and

means for simultaneously pulsing said low voltage source and said high voltage source at a specific frequency and a specific pulse duration.

2. The electrolysis system of claim 1, further comprising a system controller coupled to said electrolysis system, wherein said system controller is coupled to at least one of said low voltage source, said high voltage source, said simultaneous pulsing means, a temperature monitor contained within said electrolysis tank, a pH monitor contained within said electrolysis tank, a resistivity monitor contained within said electrolysis tank, a liquid level monitor contained within said electrolysis tank, and a flow valve within an inlet line coupled to said electrolysis tank.

3. The electrolysis system of claim 1, further comprising means for cooling said electrolysis system.

4. The electrolysis system of claim 3, wherein said cooling means is comprised of a conduit containing a heat transfer medium, wherein a portion of said conduit is in thermal communication with at least a portion of said electrolysis tank.

5. The electrolysis system of claim 1, further comprising a liquid within said electrolysis tank, wherein said liquid includes at least one of water, deuterated water, tritiated water, semiheavy water, heavy oxygen water, water containing an isotope of hydrogen, or water containing an isotope of oxygen.

6. The electrolysis system of claim 5, further comprising an electrolyte within said liquid, said electrolyte having a concentration of between 0.05 and 10.0 percent by weight.

7. The electrolysis system of claim 1, wherein said first low voltage anode is comprised of a first material, wherein said second low voltage anode is comprised of a second material, wherein said first low voltage cathode is comprised of a third material, wherein said second low voltage cathode is comprised of a fourth material, wherein said first high voltage anode is comprised of a fifth material, wherein said first high voltage cathode is comprised of a sixth material, and wherein said first, second, third, fourth, fifth and sixth materials are selected from the group consisting of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite and metal hydrides.

8. The electrolysis system of claim 1, wherein said plurality of low voltage electrodes are comprised of a first material, wherein said plurality of high voltage electrodes are comprised of a second material, and wherein said first and second materials are selected from the group consisting of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite and metal hydrides.

9. The electrolysis system of claim 1, wherein said specific pulse duration is between 0.01 and 75 percent of a time period defined by said specific frequency.

10. A method of operating a multi-cell electrolysis system comprising the steps of:

applying a low voltage to at least a first low voltage anode, a second low voltage anode, a first low voltage cathode and a second low voltage cathode contained within each of a plurality of electrolysis cells contained within an electrolysis tank of said electrolysis system, said low voltage applying step further comprising the step of pulsing said low voltage at a first frequency and with a first pulse duration; and

applying a high voltage to at least a first high voltage anode and a first high voltage cathode contained within each of said plurality of electrolysis cells, said high voltage applying step further comprising the step of pulsing said high voltage at said first frequency and with said first pulse duration, wherein said high voltage pulsing step is performed simultaneously with said low voltage pulsing step, and wherein said first high voltage anode is interposed between said first low voltage anode and said second low voltage anode within a first region of each of said plurality of electrolysis cells, and wherein said first high voltage cathode is interposed between said first low voltage cathode and said second low voltage cathode within a second region of each of said plurality of electrolysis cells.

11. A method of operating an electrolysis system comprising the steps of:

positioning a plurality of electrolysis cells within an electrolysis tank, wherein each of said electrolysis cells is comprised of a membrane dividing each of said electrolysis cells into a first region and a second region;

filling said electrolysis tank with a liquid;

positioning a plurality of low voltage electrodes within each of said plurality of electrolysis cells, wherein said plurality of low voltage electrodes is comprised of at least a first low voltage anode, a second low voltage anode, a first low voltage cathode and a second low voltage cathode, wherein said positioning step further comprises the steps of positioning said first and second low voltage anodes within said first region of each of said electrolysis cells and positioning said first and second low voltage cathodes within said second region of each of said electrolysis cells;

positioning a plurality of high voltage electrodes within each of said plurality of electrolysis cells, wherein said plurality of high voltage electrodes is comprised of at least a first high voltage anode and a first high voltage cathode, wherein said positioning step further comprises the steps of positioning said first high voltage anode between said first and second low voltage anodes within said first region of each of said electrolysis cells and positioning said first high voltage cathode between said first and second low voltage cathodes within said second region of each of said electrolysis cells;

applying a low voltage to said plurality of low voltage electrodes, said low voltage applying step further comprising the step of pulsing said low voltage at a first frequency and with a first pulse duration; and

applying a high voltage to said plurality of high voltage electrodes, said high voltage applying step further comprising the step of pulsing said high voltage at said first frequency and with said first pulse duration, and wherein said high voltage pulsing step is performed simultaneously with said low voltage pulsing step.

12. The method of claim 11, further comprising the step of selecting said liquid from the group consisting of water, deuterated water, tritiated water, semiheavy water, heavy oxygen water, water containing an isotope of hydrogen, or water containing an isotope of oxygen.

13. The method of claim 11, further comprising the steps of:

monitoring a liquid level within said electrolysis tank; and

adding more of said liquid to said electrolysis tank when said monitored liquid level falls below a preset value.

14. The method of claim 11, further comprising the step of adding an electrolyte to said liquid.

15. The method of claim 11, further comprising the steps of:

monitoring pH of said liquid within said electrolysis tank; and

adding electrolyte to said liquid when said monitored pH fails outside of a preset range.

16. The method of claim 11, further comprising the steps of:

monitoring resistivity of said liquid within said electrolysis tank; and

adding electrolyte to said liquid when said monitored resistivity falls outside of a preset range.

17. The method of claim 11, further comprising the steps of:

fabricating said plurality of low voltage electrodes from a first material;

fabricating said plurality of high voltage electrodes from a second material; and

selecting said first material and said second material from the group consisting of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite and metal hydrides.

18. The method of claim 11, further comprising the steps of:

fabricating said first low voltage anode from a first material;

fabricating said second low voltage anode from a second material;

fabricating said first low voltage cathode from a third material;

fabricating said second low voltage cathode from a fourth material;

fabricating said first high voltage anode from a fifth material;

fabricating said first high voltage cathode from a sixth material; and

selecting said first, second, third, fourth, fifth and sixth materials from the group consisting of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite, metal hydrides and alloys of steel, nickel, copper, iron, stainless steel, cobalt, manganese, zinc, titanium, platinum, palladium, aluminum, lithium, magnesium, boron, carbon, graphite, carbon-graphite and metal hydrides.

19. The method of claim 11, further comprising the step of selecting said first pulse duration to be between 0.01 and 75 percent of a time period defined by said first frequency.

20. The method of claim 11, further comprising the steps of:

monitoring a rate corresponding to said heat generation of said electrolysis system;

selecting an operating parameter from at least one of said low voltage, said high voltage, said first frequency, and said first pulse duration; and

optimizing said operating parameter of said electrolysis system in response to said monitored heat generation rate.