US20120199472A1

US20120199472A1 - System and method for electrolyzing water

Info

Publication number: US20120199472A1
Application number: US13/366,026
Authority: US
Inventors: Dan Curfew
Original assignee: Individual
Current assignee: CURFEW ELEMENTAL Inc
Priority date: 2011-02-03
Filing date: 2012-02-03
Publication date: 2012-08-09
Also published as: WO2012106631A1

Abstract

Systems and methods for electrolyzing water into hydrogen are disclosed. Hydrogen production efficiency is enhanced by maintaining a vacuum pressure on the tank holding the water being electrolyzed, and also by generating a plasma between the electrolysis plates.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. utility patent application claims the priority benefit of U.S. Provisional Patent Application Ser. No. 61/439,146, filed Feb. 3, 2011.

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to electrolysis and, more specifically, to systems and methods for electrolyzing water.

BACKGROUND OF THE INVENTION

Concerns over shortages of natural resources, such as the limited supply of traditional hydrocarbon fuels, as well as the environmental problems created by the use of such fuels, have attracted increasing attention in recent years to developing alternative fuel sources. Expectations are growing that hydrogen, a non-carbon based fuel, will serve as a clean emission fuel in the near future.
Power may be generated using hydrogen as a fuel source in different ways, including so-called fuel cells and internal combustion engines. Hydrogen fuel production has potential application in almost every sector of the economy, including district-distributed power generation, building-specific power generation for commercial buildings and homes, automobiles and other vehicles, and portable power generation equipment, just to name a few non-limiting examples. All of these applications, and automotive applications and portable instruments in particular, impose restraints on available space for the installation of the power generator, the amount of energy available to produce the hydrogen fuel, and the ability to supply and store the fuel used by the power generation equipment. Thus, a highly efficient and practical hydrogen fuel production unit will include high hydrogen storage efficiency, as well as a reduction in the external energy needed to produce the hydrogen fuel.
Unfortunately, at present, production of hydrogen from hydrocarbon sources is more efficient than hydrogen production from electrolysis of water (hydrolysis), providing little incentive for the adoption of technology to produce hydrogen from water. Therefore, improvements in the efficiency of the production of hydrogen through hydrolysis will assist in making the carbon-free fuel economy economically feasible. The present invention addresses these concerns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of one embodiment of an electrolysis system according to the presently disclosed embodiments.

FIG. 2 is a schematic block diagram of one embodiment of a power source according to the presently disclosed embodiments.

FIG. 3 is a flow chart of a method for forming electrolysis plates according to one presently disclosed embodiment.

FIG. 4 is a perspective view of two electrolysis plates coupled to two conductors according to one presently disclosed embodiment.

SUMMARY OF THE DISCLOSED EMBODIMENTS

In one embodiment, an electrolysis apparatus is disclosed, comprising an electrical power source; an electrolysis cell containing at least one anode and at least one cathode, the at least one anode and at least one cathode in electrical communication with the power source, the electrolysis cell having at least one aperture for the introduction of a fluid to undergo electrolysis; and at least one aperture for the removal of gases; at least one condensation hood disposed within the electrolysis cell; and a pump in fluid communication with the at least one aperture for the removal of gases, the pump having sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.1 atmosphere.
In another embodiment, an electrolysis apparatus is disclosed, comprising an electrical power source; an electrolysis cell containing at least one anode and at least one cathode, the at least one anode and at least one cathode in electrical communication with the power source, the electrolysis cell having at least one aperture for the introduction of a fluid to undergo electrolysis; and at least one aperture for the removal of gases; and a pump in fluid communication with the at least one aperture for the removal of gases, the pump having sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.1 atmosphere.
Other embodiments are also disclosed.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and alterations and modifications in the illustrated devices and methods, and further applications of the principles of the invention as illustrated therein are herein contemplated as would normally occur to one skilled in the art to which the invention relates.
FIG. 1 schematically illustrates one embodiment of an electrolysis system and method of the present invention, indicated generally at 10. An electrolysis cell 12 is provided for containing a quantity of liquid 14 to be electrolyzed. The electrolysis cell 12 is in the form of a cylinder in the embodiment of FIG. 1, but those skilled in the art will appreciate that electrolysis cell 12 may take any physical form, and that its shape is not critical to the present invention. The liquid 14 is supplied to the electrolysis cell 12 from tanks 16 and 18. Flow of liquid from tank 16 to electrolysis cell 12 is controlled by valve 20, while flow of liquid from tank 18 to electrolysis cell 12 is controlled by valve 22. A pressure regulating valve 24 is provided on tank 16 and a pressure regulating valve 26 is provided on tank 18. Note that the flow of liquids is also regulated by a pressure differential, resulting from a vacuum imposed upon the electrolysis cell 12, as further described hereinbelow. Thus, in certain embodiments, the pressure regulating valves 24 and 26 provide a coarse regulation of the fluid flow, which may be further regulated by a feedback loop driven by the rate at which gases are removed from the electrolysis cell 12.
Tank 18 holds a quantity of water 28 to be electrolyzed in electrolysis cell 12. Because of the robustness of the electrolysis performed according to the presently disclosed embodiments, the purity of the water 28 is not extremely critical, and water 28 may therefore comprise distilled water, filtered water, municipal tap water, sea water and the like. It will be appreciated that the use of sea water, without distillation, will produce a more caustic liquid 14. This is acceptable, though one or more modifications, as are known to those of skill in the art, may be advantageously employed in a system 10 if the intent is to employ sea water. For one example, some of the elements in the electrolysis cell 12 can be insulated, including the interior of the tank, with, for example, polytetrafluoroethylene (PTFE) or other appropriate coating to prevent contact between the sea water and the cell elements. Alternatively a thermal reactor can be employed to distill the sea water before introduction into the electrolysis cell 12; in this event, the thermal reactor may advantageously perform a dual function, as further described hereinbelow.
Tank 16 holds a quantity of liquid chemical 30 that may optionally be mixed with the water 28. Such mixing may take place prior to introduction of the liquids into the electrolysis cell 12 or, as illustrated, such mixing may take place within the electrolysis cell 12 in order to form the liquid 14 to be electrolyzed. Liquid chemical 30 may comprise any hydrocarbon, such as alcohol, gasoline, diesel fuel, or all types of ether gases if it is desired to have these hydrogenated with water to create a hydrogenated fuel source, to name just a few non-limiting examples. If only hydrogen gas is to be produced, then no hydrocarbon material is added to tank 16. If distilled or other pure water is used for the water 28, liquid chemical 30 may comprise an electrolyte, such as sodium borate dissolved in water, to name just a non-limiting example. The specific ratio of water 28 and liquid chemical 30 that is used to form electrolysis liquid 14 depends on the specific application, as will be appreciated by those skilled in the art.
Electrolysis cell 12 has a removable top 32 that may be used to securely seal the electrolysis cell 12 so that a vacuum (or negative) pressure may be maintained on the liquid 14 (discussed in greater detail hereinbelow). At least two conductive support bars 34 and 36 extend through the top 32 and into the interior chamber of the electrolysis cell 12. To the supports 34 and 36 are mounted a plurality of electrode plates 38. Alternating ones of the electrode plates 38 function as anode and cathode in the electrolysis process; therefore, the support 34 is conductively coupled to alternating ones of the plates 38, while the support 36 is conductively coupled to the remaining plates 38. Electrical isolation of alternate plates from one of the conductive support bars 34 and/or 36 may be accomplished by any suitable means, such as a non-conductive (e.g. rubber or nylon) coating, sheath, or insert, or by plates shaped with cut-outs that create a spatial separation between plate and support bar. By coupling support 34 to the ground terminal and support 36 to the positive terminal of power supply 40, appropriate voltage pulses (discussed in greater detail hereinbelow) may be advantageously applied to the electrolysis plates 38.
In certain embodiments, the conductive supports 34 and 36 are copper coated, and may use high temperature silicone or polyvinyl chloride (PVC) for corrosion protection.
Electrolysis plates 38 comprise in one embodiment 1/16th inch thick steel plates separated by 1/16th inch gaps between the plates using non-conductive spacers positioned on supports 34 and 36. In other embodiments, the electrolysis plates 38 are separated by a 1/32nd inch gap. The close spacing of the plates 38 encourages the creation of a plasma for the electrolysis process, which is believed to improve the efficiency of the electrolysis reaction. In embodiments where salt water or other caustic components are present in the liquid 14, the electrolysis plates may be formed from stainless steel. In some embodiments, the electrolysis plates 38 are plated with palladium in order to lower their resistance to the flow of electricity from power source 40. In some embodiments, the plates 38 have holes perforated therethrough. In one embodiment, the holes are ⅛th inch in diameter and spaced ⅛th inch from neighboring holes. Other hole diameters and spacings will also work. The presence of holes perforating the electrolysis plates 38 enhances the flow of ions between the plates 38 and the transport of protons and electrons, resulting in a 35-40% increase in electrolysis efficiency.
The electrodes can advantageously be made from new or recycled computer hard disk drive platters (“hard drives”). These are plentiful, inexpensive, and require little modification. Many hard drives have a palladium coating, and they generally come in thicknesses between ⅛″ and 1/22″, so all that is required to render them suitable as electrodes for the system 10 is to drill holes in them for the support bars 34 and 36. In one embodiment, a stack of hard drives is prepared by drilling a hole near one edge of the stack, the holes sized to engage corresponding threads on a support bar, and a larger cut-out on the opposite side. Alternate disks are then rotated 180 degrees, so that each of the threaded support bars 34 and 36 interface with the holes in alternating disks in the stack, and pass through the cut-outs in the other disks so as to be spatially isolated. Palladium coated hard drives have been found to make such efficient electrolysis electrodes (due to their high conductivity) that the introduction of additional holes has been found to be unnecessary. It will be appreciated that the positioning of the disks in this assembly can be controlled and maintained with the use of, e.g., threaded nuts and washers, and that electrical isolation can be assisted with the use of non-conducting elements, such as rubber inserts in the cut-outs.
This is illustrated in FIG. 3, where in step 100 a first conductor having a first diameter is provided. At step 102 a second conductor having a second diameter is provided. In one embodiment, the first conductor corresponds to the conductive support bar 34 and the second conductor corresponds to the conductive support bar 36. At step 104, a first hard disk drive platter is provided, while at step 106 a second hard disk drive platter is provided. At step 108, a first hole substantially equal to the first diameter is formed (for example, by drilling) in the first platter, such that the first conductor will engage the first hole when the first conductor is placed within the first hole. At step 110, a second hole larger than the second diameter is formed (for example, by drilling) in the first platter. At step 112, a third hole substantially equal to the second diameter is formed (for example, by drilling) in the second platter, such that the second conductor will engage the third hole when the second conductor is placed within the third hole. At step 114, a fourth hole larger than the first diameter is formed (for example, by drilling) in the second platter.
With continued reference to FIG. 3, at step 116, the first conductor is engaged with the first hole and at step 118 the second conductor is engaged with the third hole, such that the first conductor extends through the third hole without contacting the edges thereof, and the second conductor extends through the second hole without contacting the edges thereof. The final arrangement is illustrated in FIG. 5.
Power source 40 provides energy to the electrolysis plates 38 to run the electrolysis reaction. Power source 40 uses a frequency converter principle to produce pulsed direct current (DC) power. In contrast to the conventional transformer rectifier, the frequency converter design offers the advantages of lower weight and smaller physical size.
Power source 40 is illustrated schematically in FIG. 2. The input alternating current (AC) primary power 42 is passed through the circuit beaker (not shown) to a six pulse full wave bridge rectifier 44, where the input is transformed to a direct current (DC) voltage. The DC output of the rectifier 44 is fed to an inverter 46 through a series of capacitors of a switching type (not shown). Using silicon controlled rectifiers (SCRs, also known as thyristors) in the inverter 46, the DC current is switched on and off, alternating the action of charging and discharging. The control of the SCRs 46 is provided by control logic 48. In some embodiments the control logic 48 may be provided by a standard electric welding controller. The SCRs create a new alternating current (AC) at the output of the inverter 46. In one embodiment, the frequency of the switching of the SCRs varies from about 400 HZ to about 6,000 HZ, dependant upon the output load demand at the electrolysis plates 38. The greater the output required, the higher the frequency that the SCRs of the inverter 46 are switched under the control of the control logic 48. The power output is determined by the load at plates 38 for the required hydrogen production. It will be appreciated that the system of FIG. 2 variably increases the frequency of the AC signal between the input 42 and the output of the inverter 46.
The AC output of the inverter 46 is applied to the input winding of a transformer 50. The output of transformer 50 is rectified by diodes in rectifier 52 into DC output 54 that is applied to the electrolysis plates 38 for plasma generation for hydrogen production. The whole sequence of operation from the primary (AC) input 42 to the electrolysis plate 38 DC output 54 is in one embodiment regulated by control logic feedback 48. Control logic 48 keeps the plasma stabilized by analyzing the positive peaks and adjusting the system to keep them at the desired level. Because electrons continuously flow through the solution from the anode to the cathode, impurities in the solution can plate out onto the cathode, fouling the cathode and reducing the efficiency of the electrolysis system. To counteract this, the polarity of the voltages applied to the conductors 34 and 36 may be periodically reversed, even if momentarily in order to clear the fouling from the (previously designated) cathode (now anode).
The creation of the plasma between the electrolysis plates 38 creates heat, and in some embodiments provision is made for cooling the liquid 14 so that it does not turn into steam. An outlet 56 is provided in the electrolysis cell 12 for removal of a portion of the liquid 14 from the electrolysis cell 12, the liquid 14 being drawn off in one embodiment by means of a pump 58 and applied to radiator 60. Optional cooling fans 62 keep air moving over the radiator 60 in order to carry heat away from the radiator 60 and, therefore, away from the liquid 14. In one embodiment, the radiator 60 is operated so as to maintain the liquid 14 within the range of 164-188 degrees Fahrenheit. Conduit 64 then transports the cooled liquid 14 back to the interior of the electrolysis cell 12.
Hydrogen and oxygen bubbles created by the electrolysis process at electrolysis plates 38 float upward within electrolysis cell 12 and are removed therefrom at the outlet 66. Entrained within the rising hydrogen and oxygen bubbles is a quantity of water vapor and other vapors that are desirably removed from the hydrogen and oxygen. Therefore, in one embodiment, the electrolysis cell 12 includes a plurality of screens 68 through which the rising gases flow. The screens 68 have pore sizes that decrease as the rising vapors traverse the screens. In one embodiment, the first screen has pore sizes of 500 microns and the last screen has pore sizes of 1 micron. In some embodiments, the pores are formed by a mesh having square pore openings, and adjacent screens are oriented such that the axes of these square pore openings is rotated out of parallel with respect to similar axes on adjacent screens, In one embodiment, eight screens 68 are layered together and their edges fit tightly against the inside surface of the electrolysis cell 12. Screens 68 may be mounted to the supports 34 and 36. The tortuous path that the gases and water vapors must take through the screens 68 results in much of the water vapor condensing onto the screens 68 and then dripping back into the liquid 14.
Further vapor removal may be provided by one or more condensation cones 70, Condensation cone 70 also fits tightly against the interior surface of the electrolysis cell 12. Some of the water vapor rising to the underside of the condensation cone 70 will condense on the underside thereof and then slide back down the cone 70 and into the liquid 14. One or more holes 72 formed within the condensation cone 70 allow gases and vapors to reach the upper side of the condensation cone 70, where further condensation will occur, with the condensate dripping down and being channeled back to the liquid 14 by means of a series of grooves 74 formed around the exterior periphery of the condensation cones 70. In some embodiments, the grooves 74 are arcuately shaped. The grooves 74 additionally allow cooled liquid 14 that is routed back to the electrolysis cell 12 through the conduit 64 to flow back into the main portion of liquid 14.
In some embodiments, the condensation cone 70 is ¼ inch thick high temperature urethane rubber and is coated with PTFE (such as Teflon®) on both sides in order to facilitate the flow of condensed water across its surface. In some embodiments, the electrolysis cell 12 contains a plurality of stacked condensation cones 70 therein.
The hydrogen and oxygen gases produced by the electrolysis process are scavenged from the electrolysis cell 12 at the outlet 66 under a vacuum provided by vacuum source 76, such as an appropriate pump. In addition to providing a motive force for the removal of hydrogen and oxygen gases from the electrolysis cell 12, the vacuum source 76 maintains the electrolysis cell 12 under at least a partial vacuum. In one embodiment, the electrolysis cell 12 is maintained at a vacuum of greater than (i.e. lower pressure) 0.01 atmospheres. In another embodiment, the electrolysis cell 12 is maintained at a vacuum of greater than 0.03 atmospheres. In another embodiment, the electrolysis cell 12 is maintained at a vacuum of greater than 0.05 atmospheres. In another embodiment, the electrolysis cell 12 is maintained at a vacuum of greater than 0.08 atmospheres. In another embodiment, the electrolysis cell 12 is maintained at a vacuum of greater than 0.1 atmospheres. Generally, the higher the negative pressure, (i.e. the lower the pressure in the electrolysis cell 12) the more efficient the electrolysis process.
Maintaining the electrolysis cell 12 under vacuum is a contributor to the increased electrolysis efficiency of the present invention, increasing the gas generation and lowering the input power requirements. While it is not possible to change the physical properties of the water that is being electrolyzed, it is possible to change the environment in which the liquid 14 resides during electrolysis. When the molecules are under less pressure from their surrounding environment, it is easier to break the molecules apart during the electrolysis process, thereby requiring less power to run the process. In applications where the presently disclosed embodiments are used with an internal combustion engine in a vehicle, the vacuum pump 76 may be powered (directly or by a belt) by the engine, thus changing the vacuum pressure with engine speed.
Once the gases are withdrawn by the vacuum source 76, one or more optional further condensation suppression devices 78 may be employed to further remove water vapor form the gas. The condensation suppression devices 78 may contain condensation cones 70 and/or stacked screens 68 in order to provide further drying of the gases.
In some embodiments, the hydrogen and oxygen gases are heated in a thermal reactor 80 prior to injecting them into the combustion chamber. In one embodiment, thermal reactor 80 comprises a heat exchanger in which hot exhaust gases from the engine are used to heat the gases to between 400 and 1200 degrees Fahrenheit. In some embodiments, the output 82 of the thermal reactor 80 is used to route the gases to the combustion chamber of an internal combustion engine. In some embodiments, the engine may use vaporized gas injectors instead of liquid fuel injectors in order to inject quantities of gas into the combustion chamber. In the case of many diesel engines, the engines require about 30% minimum diesel fuel in order to maintain ignition and lubricate the top end of the engine. In one embodiment using a diesel engine, the hydrogen and oxygen gases are applied to the negative pressure side of the turbocharger to be injected into the engine, with the engine's fuel injectors supplying the needed quantity of diesel fuel.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

1. An electrolysis apparatus comprising:

an electrical power source;

an electrolysis cell containing at least one anode and at least one cathode, the at least one anode and at least one cathode in electrical communication with the power source, the electrolysis cell having at least one aperture for the introduction of a fluid to undergo electrolysis; and at least one aperture for the removal of gases;

at least one condensation hood disposed within the electrolysis cell; and

a pump in fluid communication with the at least one aperture for the removal of gases, the pump having sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.1 atmosphere.

2. The electrolysis apparatus of claim 1, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.08 atmosphere.

3. The electrolysis apparatus of claim 1, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.05 atmosphere.

4. The electrolysis apparatus of claim 1, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.03 atmosphere.

5. The electrolysis apparatus of claim 1, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.01 atmosphere.

6. The electrolysis apparatus of claim 1, wherein the at least one anode and at least one cathode comprise recycled palladium coated hard drives.

7. The electrolysis apparatus of claim 1, further comprising a plurality of screens within the electrolysis cell, each of the plurality of screens having pore sizes between 1 and 500 microns, and being disposed such that gases rising in the electrolysis cell pass through screens having increasingly smaller pores.

8. The electrolysis apparatus of claim 7, wherein the pores in the plurality of screens are generally square in shape, and wherein adjacent screens are oriented such that the axis of their respective pores are rotated with respect to one another.

9. The electrolysis apparatus of claim 1, wherein the at least one condensation hood is generally conical in shape, and has holes that permit gases to continue to rise above the condensation hood to exit the electrolysis cell through the at least one aperture for the removal of gases.

10. The electrolysis apparatus of claim 1, further comprising a fluid circuit for removing liquid from the electrolysis cell, cooling the liquid removed, and returning the cooled liquid to the electrolysis cell.

11. The electrolysis apparatus of claim 1, further comprising:

a first tank for holding water to undergo electrolysis, the first tank being in fluid communication with the at least one aperture for the introduction of fluid into the electrolysis cell;

a second tank for holding a liquid chemical to be mixed with the water to undergo electrolysis, the second tank being in fluid communication with the at least one aperture for the introduction of fluid into the electrolysis cell.

12. The electrolysis apparatus of claim 1, wherein the electrical power source has sufficient capacity to generate a plasma between the at least one anode and the at least one cathode.

13. An electrolysis apparatus comprising:

an electrical power source;

an electrolysis cell containing at least one anode and at least one cathode, the at least one anode and at least one cathode in electrical communication with the power source, the electrolysis cell having at least one aperture for the introduction of a fluid to undergo electrolysis; and at least one aperture for the removal of gases; and

14. The electrolysis apparatus of claim 13, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.08 atmosphere.

15. The electrolysis apparatus of claim 13, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.05 atmosphere.

16. The electrolysis apparatus of claim 13, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.03 atmosphere.

17. The electrolysis apparatus of claim 13, wherein the pump has sufficient capacity to reduce the pressure in the electrolysis cell to less than at least 0.01 atmosphere.

18. The electrolysis apparatus of claim 13, wherein the at least one anode and at least one cathode comprise recycled palladium coated hard drives.

19. The electrolysis apparatus of claim 13, further comprising a plurality of screens within the electrolysis cell, each of the plurality of screens having pore sizes between 1 and 500 microns, and being disposed such that gases rising in the electrolysis cell pass through screens having increasingly smaller pores.

20. The electrolysis apparatus of claim 14, wherein the pores in the plurality of screens are generally square in shape, and wherein adjacent screens are oriented such that the axis of their respective pores are rotated with respect to one another.

21. The electrolysis apparatus of claim 13, further comprising at least one condensation hood disposed within the electrolysis cell.

22. The electrolysis apparatus of claim 21, wherein the at least one condensation hood is generally conical in shape, and has holes that permit gases to continue to rise above the condensation hood to exit the electrolysis cell through the at least one aperture for the removal of gases.

23. The electrolysis apparatus of claim 13, further comprising a fluid circuit for removing liquid from the electrolysis cell, cooling the liquid removed, and returning the cooled liquid to the electrolysis cell.

24. The electrolysis apparatus of claim 13, further comprising:

25. The electrolysis apparatus of claim 13, wherein the electrical power source has sufficient capacity to generate a plasma between the at least one anode and the at least one cathode.