Apparatus with Cold Anode for High-Temperature Electrolytic Hydrogen Loading and Hydrogen Generation
An apparatus comprising a vessel containing an electrically conductive electrolyte. The electrolyte contains hydrogen. A cathode and anode are disposed in the electrolyte and are connected to a source of electrical power. A portion of the vessel interior is in a hot zone, and a portion is in a cool zone. The cathode is disposed in the hot zone and the anode is disposed in the cool zone. The electrolyte is in contact with both the cathode and anode and is continuous between the cathode and anode such that it conducts an electrical current between the cathode and anode. Because the anode is at a temperature lower than the cathode, anodic corrosion is greatly reduced and the apparatus can be operated continuously for long periods.
The present application claims the benefit of priority from provisional patent application 61/796,649 filed on Nov. 16, 2012 and provisional patent application 61/848,474 filed on Jan. 4, 2013, which are hereby incorporated by reference. The present application is also a continuation-in-part of copending patent application Ser. No. 13/545,983, filed on Jul. 11, 2012.
FIELD OF THE INVENTIONThe present invention relates generally to hydrogen storage materials, high temperature electrolysis, and hydrogen generation.
BACKGROUND OF THE INVENTIONHydrogen storage materials will be necessary for transporting hydrogen fuels. Such hydrogen storage materials may require loading with high pressure hydrogen gas. Accordingly, it will be necessary to investigate the properties of hydrogen storage materials under high pressure conditions, and to provide an inexpensive source of high pressure hydrogen.
Hydrogen can be produced by electrolysis of water. Electrolysis of water can be more energy efficient if it is performed at elevated temperature (e.g. above 100 C or above 250C). However, when electrolysis is performed at high temperature, the anode is corroded and oxidized rapidly. This adds considerable expense and downtime delays because corroded anodes must be replaced frequently. Also, anodic corrosion results in chemical contamination of a water electrolyte, which may contaminate and adversely affect the cathode surface, resulting in reduced efficiency at the cathode.
Accordingly, there is a need for an apparatus for electrolysis of water at high temperature, testing of hydrogen-storage materials, and hydrogen gas generation that experiences a greatly reduced rate of anodic corrosion. Such a device may also find uses in low energy nuclear reaction (LENR) research and applications.
SUMMARYThe present invention provides an apparatus for electrolysis, hydrogen loading of materials, hydrogen generation and study of low energy nuclear reaction phenomena. The apparatus comprises a hollow vessel with an interior volume. A portion of the interior volume is in a hot zone, and a portion is in a cool zone. An electrically conductive, hydrogen-containing electrolyte is disposed in the vessel. A cathode is disposed in the hot zone, and in contact with the electrolyte. An anode is disposed in the cool zone, and in the contact with the electrolyte. The electrolyte provides a path for an electrical current between the cathode and anode. The hot zone is at a temperature of at least 125 C and the cool zone is at a temperature of less than 200 C. The cool zone is at a lower temperature than the hot zone.
The vessel can comprise an anode containing electrolyte tube that extends between the hot zone and cool zone. The anode can be disposed in a distal, closed end of the anode tube.
A porous barrier can be disposed in the electrolyte and in the path of the electrical current. The porous barrier is permeable to the electrolyte and electrical current. The porous barrier tends to prevent hot electrolyte from contacting the anode.
The cathode can comprise a crucible filled with powder comprising conductive particles. The powder can comprise a mixture of metallic and ceramic particles. The power can comprise boron enriched in boron-10 or lithium.
The electrolyte may comprise water and may contain a solute to increase electrical conductivity.
The present invention provides an apparatus for electrolysis of water at high temperature, testing of hydrogen-storage materials, and high pressure hydrogen gas generation that experiences reduced anodic corrosion. The present apparatus is also useful for advancing understanding of highly hydrogen-loaded materials at high temperature. The present apparatus may also be useful for understanding hydrogen storage materials, physical properties of metal hydrides, and low energy nuclear reaction (LENR) phenomena. The present apparatus may also be useful for practical applications of LENR phenomena, such as isotope production, transmutation of elements, or energy generation.
The present invention comprises a pressure vessel containing a fluid electrolyte and having a hot zone and a cool zone. The electrolyte continuously extends between the hot zone and cool zone, thereby providing an electrical connection (e.g. an ionic electrical connection) between the hot and cool zones. A cathode is disposed in the hot zone and an anode is disposed in the cool zone. An optional porous barrier can be disposed between the hot and cool zones to provide thermal insulation between hot and cool electrolyte volumes. The present invention facilitates hydrogen-loading of the cathode and hydrogen production at high temperatures, while preventing high temperature electrolyte from contacting the anode. Because the anode is kept cool, corrosion and oxidation of the anode is greatly reduced. Consequently, the device can be continuously operated for long periods without requiring anode replacement. Also, contamination of the cathode surface by substances from the anode tends to be reduced.
Definitions
Hydrogen: Can refer to hydrogen atoms with no neutrons, a single neutron (deuterium) or two neutrons (tritium).
Electrolytically-loaded: Describes loading of hydrogen into a cathode from a liquid electrolyte, or an electrolyte operating above its critical point. The electrolyte is a source, or contains a source of hydrogen atoms or ions. The electrolyte can be water. If water is used above its critical point, the water preferably has a density of at least about 10% or 30% of the density of liquid water at room temperature.
High temperature: Above 100 C or 200 C, or above the boiling temperature of the electrolyte at atmospheric pressure.
Anode: Electrode connected to a source of current that is principally positive.
Cathode: Electrode connected to a source of current that is principally negative.
The vessel includes a headspace 24 containing water vapor, released hydrogen and oxygen, and optionally inert gases such as argon. An optional hydrogen oxidation catalyst 26 (e.g. containing platinum) is disposed in the headspace 24 and in contact with gases in the headspace 24: An electrical power supply 28 external to the vessel 20 is electrically connected to a cathode 30 and anode 32 inside the vessel. Both the cathode 30 and anode 32 must be in electrical contact with the electrolyte 22. Electrical power is provided to cathode 30 and anode 32 via cathode electrical feedthrough 37 and anode electrical feedthrough 39. It is preferable for the electrical feedthroughs 37 39 to be located in the cool zone because the feedthroughs may contain elastomeric sealing materials (e.g. Viton™ fluoroelastomer or silicone rubber) that are not tolerant of the high temperatures in the hot zone 40.
Feedthroughs 37 39 can be any conventional electrical feedthroughs for pressurized vessels.
A cathode wire 34 provides an electrical connection between the cathode 30 and the power supply 28. The cathode wire 34 may have an optional electrically insulating coating or covering 36 made of glass tubing, ceramic, metal oxide or vitreous enamel for example. The coating or covering 36 tends to prevent hydrogen loading of the wire, and therefore prevents undesirable hydrogen embrittlement of the cathode wire 34. The cathode wire is preferably electrically insulated from the pressure vessel 20 up to the point of connection with the cathode. The cathode wire 34 may comprise metal, graphite, carbon fiber or other electrically conductive material.
The pressure vessel 20 comprises an anode tube 38 and a main body 41. The anode tube 38 and main body 41 are fluidically connected. The anode tube 38 is at least partially filled with electrolyte 22 such that the anode 32 and cathode 30 are electrically connected via the electrolyte 22. The main body 41 and cathode 30 are disposed in a hot zone 40; a distal end of the anode tube 38 is disposed in a cool zone 42. Accordingly, the cathode 30 is at a higher temperature than the anode 32. Because the anode is relatively cool, the rate of corrosion of the anode 32 tends to be lower than the corrosion rate that would occur if the anode 32 was in the hot zone 40. The low corrosion rate of the anode 32 is a substantial advantage and goal of the present invention.
Preferably, both the anode and cathode are electrically isolated from (i.e. not in electrical contact with) the pressure vessel 20.
An inner surface of the anode tube may have an optional electrically insulating coating 44. The coating may comprise glass, enamel, vitreous enamel, polymers or ceramic for example. The coating protects the inner surface of the anode tube 38 from corrosion in the vicinity of the anode 32. The coating 44 may extend to cover the entier interior surface of the vessel 20.
The pressure vessel 20 may be made of steel, stainless steel, or nickel superalloys for example. The pressure vessel should be resistant to water corrosion and oxygen at high temperature. Optionally, the entire inner surface of the pressure vessel can be coated with a protective material such as glass, enamel, ceramic, vitreous enamel or the like.
The cathode 30 can be made of any material under investigation for its hydrogen loading, cathodic hydrogen generation or hydrogen permeability properties. The present invention is not limited to any particular structure or composition of the cathode material. Exemplary materials that can be used in the cathode include palladium, nickel, titanium, carbon nanotubes, niobium, or metallic glasses (e.g. zirconium-based metallic glasses) and alloys and compounds thereof. Materials of particular interest include materials with a high hydogen loading capability, or efficient hydrogen production capability or high hydrogen permeability, or that are known to produce low energy nuclear reactions (LENRs).
The anode 32 may comprise an electrically conductive material resistant to anodic corrosion such as platinum, graphite, Pt-coated titanium, palladium, carbon nanotubes, stainless steel or conductive oxide ceramics (e.g. lanthanum niobate).
However, in some embodiments, it may be desired to use anode materials that do corrode somewhat, such that anode material is dissolved in the electrolyte and is later electrodeposited on the cathode. In this case, the lower temperature in the cool zone may provide a desired reduced rate of anodic corrosion.
Power supply 28 may provide DC power, pulsed DC power, or intermittent reversed power, as known in the electroplating arts.
The pressure vessel can operate over a wide range of temperatures and pressures, for example, up to 600 C and 5000 PSI. The electrolyte can be in a subcritical or supercritical state. The electrolyte can be water and may contain a solute such as lithium hydroxide to increase electrical conductivity. Alternatively, the electrolyte can be high purity water that does not contain a solute. Preferably, if the electrolyte is water and a solute is present, the solute is selected such that oxygen is produced at the anode 32.
The hot zone and cathode can be at a temperature higher than 125 C 150C or 200 C, and the cool zone and anode can be at a temperature lower than 200 C 150 C or 100 C. In all embodiments, the anode must be at a temperature lower than the cathode.
If the present apparatus is operated in the subcritical state (i.e. below 374 C for water), it is preferably for both the cathode and anode to be fully submerged in the liquid phase. If the present apparatus is operated in the supercritical state (i.e. above 374 C for water), it is preferable for the density of the water fluid to have a density of at least 30% or 60% the density of liquid water at room temperature.
It is noted that supercritical pure water has a relatively high electrical resistivity (e.g. 115 mega-ohm-cm at 374 C versus 0.413 mega-ohm-cm at 300 C). Consequently, it may be necessary to dissolve salts in the supercritical water to increase electrical conductivity, or use a power supply with a higher operating voltage.
Other electrolyte materials can also be used such as molten salts or ionic liquids. However, the electrolyte must contain hydrogen (as a constituent of the electrolyte molecule or dissolved in the electrolyte) that is evolved from and/or loaded into the cathode during operation.
The hot zone 40 is generally at a temperature suitable for increasing the rate of hydrogen loading of the cathode (e.g. by removing a surface oxide layer), increasing the energy efficiency of hydrogen generation, or increasing the rate of LENR phenomena, or chemically reducing metal oxides on the cathode surface. The cool zone 42 is generally at a temperature suitable for reducing the rate of anode corrosion to a tolerable or desirable level. Also, the cool zone 42 can be at a temperature low enough to avoid thermal damage to cathode and anode feedthroughs 37 39.
In operation, power supply 28 drives an electrical current between cathode 30 and anode 32, creating an ionic current 45 that flows through the anode tube 38. In the case of a water electrolyte, hydrogen 46 is generated at the cathode 30 and oxygen 48 is generated at the anode 32. Hydrogen gas 46 and oxygen gas 48 rise into the headspace 24. The oxygen gas 48 flows through the anode tube 38 into the hot zone 40 to reach the headspace 24. The hydrogen 46 and oxygen 48 are combined into water vapor at the Pt catalyst 26. A portion of the generated hydrogen enters the cathode 30, resulting in substantial, measurable changes to the cathode material properties, and possibly LENR phenomena, as known in the art.
The cathode 30 can be studied with known techniques, such as electrical resistance measurements, optical probes or calorimetry for example. Many different types of sensors or electrical probes (not shown) can be connected to the cathode 30 or disposed in the hot zone, as known in the art.
A substantial advantage of the present invention is that the apparatus can be operated without exposing the anode 32 to the high temperature present in the hot zone. This tends to greatly reduce the rate of anodic corrosion of the anode. Consequently, the present apparatus can be continuously operated for long durations. Also consequently, little of the anode material is electrodeposited on the cathode surface. The present apparatus therefore enables prolonged study and usage of the hydrogen-loaded cathode, and long-duration continuous hydrogen production.
In operation, hydrogen 46 is produced at the cathode 30. Some hydrogen enters the cathode 30 and diffuses through the cathode material into the cavity 52. Because the cathode 30 is at high temperature, the hydrogen diffusion rate is increased and the cavity rapidly fills with hydrogen. Extremely high pressures can be obtained inside the cavity 52, such as 5,000 atmospheres or more. High pressure hydrogen is provided from the tube 54, external to the pressure vessel 20. The present apparatus of
Because the anode 32 is not exposed to the high temperature in the hot zone, anode corrosion is greatly reduced. Consequently, the anode 32 can operate for longer periods before requiring replacement, and less anode material is dissolved into the electrolyte, resulting in less contamination on the surface of the cathode 30. Also, energy efficiency will be improved.
It is noted that the porous barrier 63 may have a small tube 64 for allowing the escape of oxygen bubbles or other gases created at the anode 32.
Alternatively, the porous barrier 63 may block the flow of oxygen bubbles, and thereby direct oxygen towards the valve 47 in the embodiment of
In some applications of the present invention, it may be desirable to use pure water or deionized water (i.e. lacking a solute) as the electrolyte. Pure water has a relatively high electrical conductivity at high (but subcritical) temperatures present in the hot zone 41. However, pure water in the cool zone 42 may have a much lower electrical conductivity that is too low for efficient operation. Consequently, it may be desirable for the electrolyte on the hot/cathode side of the barrier 63 to have a lower solute concentration than the electrolyte on the cool/anode side of the barrier 63. However, this creates a new problem of maintaining the solute concentration gradient across the porous barrier 63. Without an active system for maintaining the concentration gradient, eventually the solute concentration will become equal on both sides of the barrier 63.
Alternatively, the reverse osmosis system can be replaced with a distillation device for separating pure water and concentrated solute solution.
In the embodiment of
In operation, hydrogen is generated inside the powder 60, for example optionally near the boundary of the crucible 62 and powder 60. During operation, particles within the powder can become loaded with hydrogen. Hydrogen bubbles can rise through the powder 60 or can escape through the porous walls of the crucible 62.
An advantage of the embodiment of
The powder 60 in the crucible 62 can comprise a mixture of conductive and nonconductive powders, such as a mixture of metallic and ceramic particles. Ceramic particles can comprise alumina, zirconia, zeolites, niobates, titanates or silica powder for example. Conductive powders can comprise metals (e.g. palladium, nickel, niobium, vanadium, titanium), metallic glasses, carbon nanotubes, graphene, electroceramics or intermetallics for example. The conductive powder can also comprise other materials possibly suitable for hydrogen storage or suitable as a cathode material for water electrolysis or suitable for accelerating LENR reactions (e.g. boron-10, boron-containing ceramics or lithium-containing ceramics such as lithium niobate or lithium titanate). The powder particles can have many shapes, such as flakes, fibers, dendrites, nanowires, nanoribbons or the like. The powder particles can have a wide range of sizes, such as 1 nm-100 microns, for example.
Preferably, the content of conductive particles is high enough such that the powder 60 has some bulk electrical conductivity. In some embodiments, the conductivity will not extend to the inner surface of the crucible 62, but instead conductive paths from the wire 34 through the conductive particles will almost all terminate in the bulk of the powder 60.
Percolation theory holds that the probability of a continuous conductive path (i.e. through randomly distributed conductive particles) decreases exponentially with distance. Accordingly, the “cathodic surface” where the cathodic half reaction occurs will not necessarily be a 2-D surface, but rather will be a 3-dimensional volume in the vicity of the illustrated cathodic surface. The location and distribution of the cathodic surface will depend on the morphology, size, and proportion of the conductive particles.
A possible shortcoming of the embodiment of
Mixing of the powder 60 during operation will continuously expose new conductive particles to the cathodic surface where, electrochemical reactions are occurring. In this way, the lifetime of the cathode is extended, and all conductive particles in the powder 60 have an opportunity to spend some time at the cathodic surface involved in the cathodic reactions.
It is noted that in some embodiments the pressure vessel may also be loaded with pressurized hydrogen gas. This hydrogen gas can be dissolved in the electrolyte.
Preferably in the present invention the electrolyte is a fluid or liquid.
Preferably, the cathode is at least 50 C, 100 C, or 150 C hotter than the anode.
UtilityAs noted above, the present invention is useful for generating high pressure hydrogen gas, for efficiently electrolysing water, and for investigating hydrogen storage materials.
The present invention is also useful for basic research of highly hydrogen-loaded metals and materials at high temperature. Such investigations are particularly useful for exploring materials for hydrogen energy storage, for example.
Also, the present invention may be useful for research into low energy nuclear reaction (LENR) and cold fusion phenomena and applications thereof Such applications may include transmutation of elements, new element production, new isotope production, and energy production.
The above embodiments may be altered in many ways without departing from the scope of the invention. Accordingly, the scope of the invention should be determined by the following claims and their legal equivalents.
Claims
1. An apparatus for electrolysis and hydrogen loading, comprising:
- a) a hollow vessel with an interior volume, wherein a portion of the interior volume is in a hot zone and a portion of the interior volume is in a cool zone;
- b) an electrically conductive electrolyte disposed in the vessel;
- c) a cathode disposed inside the vessel in the hot zone, and in contact with the conductive electrolyte;
- d) an anode disposed inside the vessel in the cool zone, and in contact with the conductive electrolyte
- wherein the hot zone is at a temperature of at least 125 C, and the cool zone is at a temperature of at most 200 C, and the cathode is at least 25 C hotter than the anode; and
- wherein the electrolyte is fluidically continuous between the hot zone and the cool zone such that the electrolyte conducts an electrical current between the anode and cathode.
2. The apparatus of claim 1 further comprising an anode tube that extends between the hot zone and cool zone, wherein the anode tube contains the electrolyte that conducts an electrical current between the anode and cathode.
3. The apparatus of claim 1 further comprising an anode electrical feedthrough disposed in the cool zone, and a cathode electrical feedthrough disposed in the cool zone.
4. The apparatus of claim 1 further comprising a porous barrier disposed in the path of the electrical current, wherein the porous barrier is conductive to an ionic current flowing through the electrolyte.
5. The apparatus of claim 4 wherein electrolyte on a cool anode side of the porous barrier contains an ionic solute for increasing electrical conductivity, and electrolyte on a hot cathode side of the porous barrier contains a lower concentration of the ionic solute.
6. The apparatus of claim 1 wherein the cathode comprises a crucible comprising electrically insulating material with at least one porous sidewall, and and a powder comprising electrically conductive particles disposed in the crucible.
7. The apparatus of claim 6 wherein the powder contains boron enriched in boron-10 or lithium.
8. The apparatus of claim 1 wherein the hot zone is at a temperature of at least 200 C, and the cool zone is at a temperature of at most 150 C.
9. An apparatus for electrolysis and hydrogen loading, comprising:
- a) a hollow vessel with an interior volume, wherein a portion of the interior volume is in a hot zone and a portion of the interior volume is in a cool zone;
- b) an electrically conductive electrolyte disposed in the vessel;
- c) a cathode disposed inside the vessel in the hot zone, and in contact with the conductive electrolyte, wherein the cathode comprises a crucible with at least one porous wall permeable to the electrolyte and conductive to electrical current in the electrolyte, and a powder comprising electrically conductive particles disposed in the crucible;
- d) an anode disposed inside the vessel in the cool zone, and in contact with the conductive electrolyte
- wherein the hot zone is at a temperature of at least 125 C, and the cool zone is at a temperature of at most 200 C, and the cathode is at least 50 C hotter than the anode; and
- wherein the electrolyte is fluidically continuous between the hot zone and the cool zone such that the electrolyte conducts an electrical current between the anode and cathode.
10. The apparatus of claim 1 further comprising an anode tube that extends between the hot zone and cool zone, wherein the anode tube contains the electrolyte that conducts an electrical current between the anode and cathode.
11. The apparatus of claim 9 further comprising a porous barrier disposed in the path of the electrical current, wherein the porous barrier is conductive to an ionic current flowing through the electrolyte.
12. The apparatus of claim 11 wherein electrolyte on a cool anode side of the porous barrier contains an ionic solute for increasing electrical conductivity, and electrolyte on a hot cathode side of the porous barrier contains a lower concentration of the ionic solute.
13. The apparatus of claim 9 wherein the powder comprises a mixture of conductive particles and nonconductive particles.
14. The apparatus of claim 9 wherein the powder contains boron enriched in boron-10 or lithium.
15. The apparatus of claim 9 wherein the hot zone is at a temperature of at least 200 C, and the cool zone is at a temperature of at most 150 C.
16. An apparatus for electrolysis and hydrogen loading, comprising:
- a) a hollow vessel with an interior volume, wherein a portion of the interior volume is in a hot zone and a portion of the interior volume is in a cool zone;
- b) a hydrogen-containing, conductive electrolyte disposed in the vessel;
- c) a cathode disposed inside the vessel in the hot zone, and in contact with the conductive electrolyte,
- d) an anode disposed inside the vessel in the cool zone, and in contact with the conductive electrolyte
- wherein the hot zone is at a temperature of at least 125 C, and the cool zone is at a temperature of at most 200 C, and the cathode is at least 25 C hotter than the anode; and
- wherein the electrolyte is fluidically continuous between the hot zone and the cool zone such that the electrolyte conducts an electrical current between the anode and cathode;
- 5) an electrical power supply electrically connected to the cathode and anode.
17. The apparatus of claim 16 further comprising an anode tube that extends between the hot zone and cool zone, wherein the anode tube contains the electrolyte that conducts an electrical current between the anode and cathode.
18. The apparatus of claim 16 further comprising a porous barrier disposed in the path of the electrical current, wherein the porous barrier is conductive to an ionic current flowing through the electrolyte.
19. The apparatus of claim 16 wherein the cathode comprises a crucible comprising electrically insulating material with at least one porous sidewall, and a powder comprising electrically conductive particles disposed in the crucible.
20. The apparatus of claim 19 wherein the powder contains boron enriched in boron-10 or lithium.
Type: Application
Filed: Nov 17, 2013
Publication Date: May 21, 2015
Inventor: Dan Steinberg (Blacksburg, VA)
Application Number: 14/082,184
International Classification: C25B 13/00 (20060101); C25B 1/04 (20060101);