Apparatus and method for creating a hydrogen network using water treatment facilities
The invention is an apparatus and method for producing two chemical products, hypochlorite for use as a sanitizing solution and hydrogen as a fuel source for vehicles, and a system to create a hydrogen fuel network therefrom.
This application is a continuation-in-part of U.S. application Ser. No. 10/810,551, filed Mar. 29, 2004, currently pending, the entire disclosure of which is incorporated herein be reference.
FIELD OF THE INVENTIONThis invention is in the field of hydrogen and hypochlorite production and distribution.
BACKGROUND OF THE INVENTIONHydrogen is widely used for industrial purposes and its production is concentrated in large facilities, in a small number of geographic locations. Hydrogen and hydrogen production is not widely distributed geographically. Geographic distribution of hydrogen is essential for the development of transportation or distributed power generation applications.
Hydrogen is a difficult substance to transport from location to location due to its chemical properties. At room temperature its density is very low and must be compressed or chilled to achieve a useable energy density. Hydrogen is highly combustible and explosive. It is a gas at atmospheric pressure, and becomes a liquid only at extremely high pressures. Hydrogen can embrittle steel and other metals, making it difficult to handle.
Transportation via rail or truck is also inefficient as the amount of energy used in transportation can make up a large percentage of the energy available from the hydrogen itself. Hydrogen is dangerous to transport due to the requirement to store it at high pressures along with the explosiveness of the gas.
Local production of hydrogen, mostly for transportation, is used on a very small scale, generally as pilot projects. Without sufficient demand for local hydrogen production the growth of these stations will be limited. Without sufficient supply of local hydrogen the adoption of hydrogen fueled devices and local power generation applications will be limited.
Current hydrogen vehicles have limited range and typically require large fuel tanks to store compressed hydrogen. Hydrogen can be stored either as a gas, as a liquid, or in a solid state storage. Gas storage requires energy to compress the gas for storage in a high-pressure vessel, and typically requires relatively large tanks. Because of the increased pressure, gas storage may pose a greater threat of leakage and the possibility of an explosion. Liquefaction of hydrogen consumes a significant amount of energy. Hydrogen can also be stored using solid state hydrogen storage technology, such as metal hydride solid hydrogen storage. A metal hydride is formed when hydrogen reacts with the metal ions in a storage alloy, in an exothermic reaction. When heat is applied to the system, the reverse reaction occurs, and hydrogen is released from the metal hydride alloy for use.
Hydrogen is typically used to generate power for transportation needs either by using a process of combustion with oxygen to generate mechanical energy and heat, or fuel cell technologies, where typically protons, but not electrons, are diffused through a membrane, generating an electrical current and heat.
There is a need to provide a geographically distributed network of hydrogen production, storage, and dispensing to facilitate the development of a hydrogen fuel infrastructure network and a distributed hydrogen power generation network. Hydrogen fuel stations need to be abundant and accessible.
One of the most geographically distributed industries is the water and wastewater treatment industry. A large number of these treatment plants use hypochlorite in their processes, or could use it as a substitute for other products. As shown by the art of this field, hypochlorite can be produced on-site at individual water or wastewater treatment plants through an electrolytic process that evolves hydrogen as a waste by-product.
Chlorine in the form of hypochlorite, typically sodium hypochlorite, has been used in the field of water treatment for over a century. Hypochlorite is an alternative to the use of chlorine gas for disinfecting water. Prior to the use of hypochlorite, chlorine gas was primarily used as a chlorine source for disinfecting water. The transportation of chlorine gas is a safety concern, so sodium hypochlorite is now often used as an alternative source of chlorine, as it is relatively safe to transport.
On-site sodium hypochlorite generation has been used as a relatively safe and cost efficient way of providing chlorine for water treatment applications. Sodium hypochlorite is made by reacting sodium chloride and water in the presence of a DC current according to the following equation 1:
NaCl+H2O+2e−→NaOCl+H2
Previous systems of on-site sodium hypochlorite generation have vented away the H2 produced into the atmosphere.
U.S. Pat. No. 6,468,412 illustrates a hypochlorite production system. The system includes an electrolyzer that requires a source of brine which may be either a synthetic source such as a salt saturator or a natural source such as sea water. The brine is metered by a pump into the electrolyzer containing electrolytic cell where electrolysis occurs. The electrolytic cell contains cathodes and anodes. A separate softened water supply may be provided to the electrolyzer to optimize the brine concentration within. The resultant hypochlorite solution is transferred past product outlet and travels through solution line to storage tank.
Hydrogen gas, produced in addition to hypochlorite in the electrolyzer, passes with the hypochlorite solution through solution line into the storage tank where it separates from the liquid product. In other embodiments some separation may occur in the electrolyzer itself with a gas vent connected to the top of the electrolyzer allowing for the venting of hydrogen gas directly from the electrolyzer into the atmosphere. An air blower may also be connected to the storage tank to provide a forced flow of air to purge the hydrogen in the storage tank into atmosphere. In further embodiments a fan may be attached to individual electrolyzers. In the prior art, hydrogen is thus not collected for future use.
There is a need to provide a way to collect and use the hydrogen produced during hypochlorite production such as to remove or minimize the disadvantages mentioned above.
SUMMARY OF THE INVENTIONThe invention relates to apparatus and method for producing hypochlorite for use as a sanitizing solution in water and waste-water treatment and hydrogen as a fuel source for vehicles, as part of a hydrogen infrastructure. By producing and collecting hydrogen as part of water and waste-water treatment, a network of fueling stations can be provided near inhabited areas to supply hydrogen to vehicles without the problems typically associated with mass hydrogen fuel transportation and production.
The proximity of treatment plants to population centers make these locations ideal for producing hydrogen locally, to address local demand without the costs and dangers associated with hydrogen transportation. When a number of treatment plants have been adapted to conform to the invention, a wide area network of hydrogen production, storage, and dispensing can be created. Given the existing technologies available for use in the water and wastewater treatment industry that produce hydrogen as a waste gas, one can intuitively see the inventive and valuable nature of this invention as a means of creating a hydrogen production, storage, and dispensing network through the capture of what was formerly considered a waste gas currently produced at a large number of water or wastewater treatment plants.
An apparatus for producing hypochlorite and hydrogen from brine to enable the transfer of hydrogen to another location comprising:
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- an electrolyzer that generates hypochlorite and hydrogen, which received brine from a source of brine, and, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine, the electrolyzer having an electrolyzer outlet for transporting hypochlorite in solution with spent brine, and generated hydrogen;
- a separator that receives the hypochlorite in solution with spent brine, and generated hydrogen from the electrolyser, and separates spent brine in solution with hypochlorite from hydrogen;
- a hydrogen conduit coupled to the separator that transports hydrogen separated by the separator to a hydrogen storage system; and
- a hydrogen transfer device coupled to the hydrogen storage system for transferring hydrogen from the hydrogen storage system.
A method for producing hypochlorite and hydrogen comprising the steps of:
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- producing hypochlorite and hydrogen in an electrolyzer from brine received from a source of brine, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine;
- separating in a separator spent brine and hypochlorite in solution, and generated hydrogen received from the electrolyzer;
- directing generated hypochlorite from the separator to a hypochlorite storage,
- directing generated hydrogen from the separator to a hydrogen storage, and
- filling a storage tank in or on a vehicle with hydrogen from the hydrogen storage.
A distribution network for production, storage, and dispensing hydrogen gas, comprising:
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- a plurality of water treatment devices, each device having:
- an electrolyzer that generates hypochlorite and hydrogen, which received brine from a source of brine, and, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine;
- a separator that receives the hypochlorite in solution with spent brine and generated hydrogen from the electrolyzer, and separates spent brine in solution with hypochlorite from hydrogen;
- a hydrogen conduit coupled to the separator that transports hydrogen separated by the separator to a hydrogen storage system; and
- a hydrogen transfer device coupled to the hydrogen storage system for transferring hydrogen from the hydrogen storage system;
- wherein the hydrogen transfer device is designed to transfer hydrogen from the hydrogen storage system to a storage tank in or on a vehicle;
- wherein at least one of the water treatment devices is located at a first water or waste water treatment facility; and
- wherein at least one of the water treatment devices is located at a second water or waste water treatment facility located a distance away from the first water or waste water treatment facility.
- a plurality of water treatment devices, each device having:
Other features of the invention will be evident from the disclosure of several embodiments that follows.
BRIEF DESCRIPTION OF THE DRAWINGSEmbodiments of the invention will be described by way of example and with reference to the drawings in which:
The present invention is generally directed to an integrated system for generating both a disinfecting agent, and the production of gaseous hydrogen for use in vehicles or other devices requiring a high energy density power supply. Many of the specific details of certain embodiments of the invention are set forth in the following description and in FIGS. 1 to 6 to provide a thorough understanding of such embodiments. One who is skilled in the art will understand, however, that the present invention may have additional embodiments, or that the present invention may be practiced without several of the details described in the following description.
The electrolysis process is well known, and produces hypochlorite in solution with spent brine, and hydrogen. The hypochlorite in solution with spent brine, and the hydrogen in gaseous form, flow out of the electrolyzer 103 through the electrolyzer outlet 104 to the separator 105.
In the separator 105, typically a large tank, the hydrogen gas is drawn from the top of the tank as it bubbles out of the spent brine solution, and flows along a hydrogen conduit 106 to a hydrogen storage system 107.
As needed, the hydrogen storage system 107 is coupled to a hydrogen transfer device 110. The hydrogen transfer device 110 may be a simple flow control valve and mechanical coupling device designed to safely couple with a hydrogen storage tank in or on a vehicle. It is conceived that the hydrogen stored in the hydrogen storage tank in the vehicle is used to power the vehicle, or is transported elsewhere for further use. An example of a further use might be to fuel other vehicles, or to provide fuel for a electrical power generator.
From the separator 105, the hypochlorite in solution with spent brine flows along a spent brine conduit 108 to a hypochlorite storage 109. The hypochlorite in solution with spent brine may be further processed, or used as is, to sanitize water or waste water in accordance with know methods for treating water or waste water, or may be sold commercially.
In the brine electrolyzer/separator assembly 203, electrolysis occurs and separation is permitted to happen all within one assembly. Hypochlorite in solution with spent brine, and the hydrogen in gaseous form, flow out of the electrolyzer/separator assembly 203 through hydrogen and spent brine conduits 206 208 to the hydrogen storage system 207 and the hypochlorite storage 208.
As needed, the hydrogen storage system 207 is coupled to a hydrogen transfer device 210. The hydrogen transfer device 210 is designed to safely couple with a hydrogen storage tank in or on a vehicle.
The hydrogen stored in the one or more hydrogen storage vessels 312 may be controllably transferred to a storage tank in or on a vehicle using the hydrogen transfer device 310. Alternatively, the hydrogen can also be stored using solid state hydrogen storage technology, such as metal hydride solid hydrogen storage (not shown).
Electrolysis occurs within the electrolyzer 403, and hypochlorite in solution with spent brine and the hydrogen in gaseous form flow out of the electrolyzer 403 through the electrolyzer outlet 404 to the separator 405. Some hydrogen may bubble out of the spent brine solution in the electrolyzer 403, and is carried away using a first duct 415 to a hydrogen purification subsystem 417.
Hydrogen is separated from the hypochlorite in solution with the spent brine in the separator 405, and flows through a second duct 416 to the hydrogen purification subsystem 417. The hydrogen is purified in the hydrogen purification subsystem 417 to remove any non-combustible gases, such as atmospheric air, nitrogen, or carbon dioxide, using known methods.
Instead of using a separate hypochlorite storage, the separator 405 may act as a storage for the hypochlorite in solution with the spent brine, so that the spent brine conduit 408 directs the hypochlorite in solution with the spent brine directly away for use in water or waste water treatment.
After the hydrogen is purified by the hydrogen purification subsystem 417, the hydrogen flows through the hydrogen conduit 406 to the hydrogen storage system 407.
One or more dedicated water electrolyzers 413 are also fed by the electricity source 402, and electrolyze water to produce hydrogen using known techniques. The evolved hydrogen may be directly stored in the hydrogen storage system 407 along with hydrogen from the hydrogen purification subsystem 417. Alternatively, the evolved hydrogen from the one or more dedicated water electrolyzers 413 may be directed to the hydrogen purification subsystem 417. The oxygen evolved from one or more dedicated water electrolyzers 413 could be vented or captured for subsequent use (not shown).
As needed, the stored hydrogen in the hydrogen storage subsystem 417 maybe be controllably transferred to a storage tank in or on a vehicle using a fueling device 414, which in this embodiment comprises the hydrogen transfer system.
Operation of the apparatus 500 may require water to be delivered to a water deionizer 501. The source of the water may be either potable or non-potable. The flow rate of the water may be dictated by various factors and may include but not be limited to the level of hypochlorite in the storage vessel 503 or the dosing rate of the metering pump 514. Once the water has been softened to a sufficient level it is delivered to salt saturator 502 where salt is added to the water to create a brine solution that is input into the electrolyzer 503. Within the electrolyzer 503 a direct current is applied to cause the brine solution to evolve into hypochlorite and hydrogen in accordance with Equation 1 above. Electrical connections and power conversion devices are not shown but implied.
In the electrolysis process, hypochlorite and hydrogen are evolved and flow as a two-phase mixture out of the electrolyzer 503 into the hypochlorite storage vessel 504 where phase separation into liquid hypochlorite solution 505 and gaseous hydrogen 506 occurs. Some separation may occur within the electrolyzer 503 itself and any separated hydrogen may be vented out of individual electrolyzers via a vent line 519 directly into the hypochlorite storage vessel 504 to increase the efficiency of any downstream electrolyzers. Additionally, dedicated phase separators and condensers may be employed to purify the hydrogen but are not shown on the diagram. A gas outlet valve 507 allows for evolved hydrogen to be vented to atmosphere in the case of a failure of the hydrogen storage system or the hydrogen fuel cell. A fan that is not shown may be used to purge the system of hydrogen under any alarm conditions in conjunction with the opening of the outlet valve 507. Check valve 508 prevents the backflow of hydrogen back into the storage vessel 504.
When the hydrogen gas has been sufficiently purified it may pass through vacuum regulator 516 to compressor 509. The compressor 506 transfers the hydrogen to storage or directly into a proton exchange membrane fuel cell. Pressure sensor 518 monitors the pressure in the storage system and may be used in controlling the operation of the system. Control valve 510 is used to dictate the direction of gas flow either into the hydrogen storage system 515 or through pressure regulator 517 and then to a proton exchange membrane fuel cell (not shown). A plurality of vessels 511 may be utilized in storing the hydrogen. Safety relief valve 512 is attached at the manifold of the pressure vessels to expulse any excess pressure and prevent vessel rupture. Burst discs (not shown) may also be included on the pressure vessels. The flow of hydrogen from the pressure vessels 512 to a proton exchange membrane fuel cell may be controlled by a pressure regulator 513.
Operation of the apparatus 600 requires a source of water to be delivered to a water deionizer 601 as with the other preferred embodiment discussed. The source of the water may be either potable or non-potable. Softened water from the water deionizer 601 is supplied to salt saturator 603 to create a brine solution. Softened water may similarly distributed to proton exchange membrane fuel cell 637 through valve 602 and supply line 629 to cool the fuel cell 637 and also to electrolyzer 604 through water line 634 to dilute the brine concentration in the electrolyzer 604 if necessary. Brine created in the salt saturator 603 is metered into electrolyzer 604 where a direct current is applied to the solution in order to evolve hypochlorite and hydrogen. A series of electrolyzers 604 is shown in
Within the hypochlorite storage and hydrogen separation vessel 607, two distinct phases are present: the liquid hypochlorite phase 608 and the gaseous hydrogen phase 609. The liquid hypochlorite phase 608 is metered as a disinfecting agent into a water system by metering pump 633 but could also be transferred to another storage device to be transported to an off-site (disinfection) system, or sold commercially. A gas outlet valve 610 is attached to the top of the vessel 607 allowing for evolved hydrogen to be vented to atmosphere in the event of a failure of the hydrogen storage system 616 or the fuel cell 637. A fan (not shown) may be connected to the vessel 607 to purge any evolved hydrogen into the atmosphere through gas outlet valve 610 during an alarm condition.
Successive hydrogen purification mechanisms (not shown) may be used in addition to the primary separation vessel 607. When the hydrogen gas has been sufficiently purified it will pass through vacuum regulator 612 to compressor 613. An optional check valve 611 will prevent the backflow of hydrogen. The compressor 613 provides the necessary pressure to store the hydrogen as compressed gas or feed the gas directly to the fuel cell 637. Pressure sensor 614 monitors the pressure in the hydrogen storage system 616 and may be used in the control scheme of the entire system. Control valve 615 is used to direct the flow of hydrogen to either the hydrogen storage system 616 or the fuel cell 637 or proportionally to both. A plurality of pressure vessels 617 may be employed based on the demands of the system 600. A safety relief valve 638 is attached at the manifold of the pressure vessels 617 to expulse any excess pressure and prevent a vessel 617 rupture. Pressure regulator 618 may be used to control the flow of hydrogen from the pressure vessels 617 to the fuel cell 637. Likewise pressure regulator 620 may be used to control the flow of hydrogen from the compressor 613 to the fuel cell 637.
Isolation control valves 619 and 635 allow for the selection of either the stored or direct source of hydrogen for the fuel cell 637. Hydrogen fuel flows into the humidification module 622 of the fuel cell 637 through hydrogen inlet 621. The chosen oxidizer flows into the humidification module 622 of the fuel cell 637 through oxidizer inlet 631. Softened water from deionizer 601 is transferred to the fuel cell 637 for humidification and cooling through water supply line 629. The water is removed from the fuel cell 637 via water waste line 630. Humidified hydrogen and oxidizer are transferred into the electrochemically active module 623 where the electrochemical reaction creates a potential difference between positive electrode 624 and negative electrode 625. The potential difference across the electrodes 624 625 produces a DC which is accepted by power handling module 627 where it could be applied directly to a load (not shown) or converted to AC current by power-conditioning module 628 and then applied to a load.
Unused hydrogen from the electrochemical reaction may be re-circulated back through the system 600 via hydrogen return line 626 or it may be exhausted to atmosphere through a gas outlet valve that is not shown. Check valve 636 prevents the backflow of hydrogen. Oxidizer that is not reacted is exhausted to atmosphere through the oxidizer outlet 632.
It will be appreciated that the above description relates to the preferred embodiments by way of example only. Many variations on the system and method for delivering the invention without departing from the spirit of same will be clear to those knowledgeable in the field, and such variations are within the scope of the invention as described and claimed, whether or not expressly described.
Claims
1. An apparatus for producing hypochlorite and hydrogen from brine to enable the transfer of hydrogen to another location comprising:
- a. an electrolyzer that generates hypochlorite and hydrogen, which received brine from a source of brine, and, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine, the electrolyzer having an electrolyzer outlet for transporting hypochlorite in solution with spent brine, and generated hydrogen;
- b. a separator that receives the hypochlorite in solution with spent brine, and generated hydrogen from the electrolyser, and separates spent brine in solution with hypochlorite from hydrogen;
- c. a hydrogen conduit coupled to the separator that transports hydrogen separated by the separator to a hydrogen storage system; and
- d. a hydrogen transfer device coupled to the hydrogen storage system for transferring hydrogen from the hydrogen storage system.
2. The apparatus of claim 1, where the source of brine comprises:
- a. a deionizer for deionizing water in fluid communication with a source of water;
- b. a salt saturator for producing brine from the water deionized by the deionizer.
3. The apparatus of claim 1, comprising a pump which draws hypochlorite in solution with spent brine from the separator for feeding hypochlorite in solution with spent brine into a water or wastewater treatment system.
4. The apparatus of claim 1, wherein the hydrogen storage system comprises a compressor coupled to at least one storage vessel structured to contain hydrogen.
5. The apparatus of claim 1, where the hydrogen storage system comprises a chiller coupled to at least one storage vessel structured to contain hydrogen.
6. The apparatus of claim 1, where the hydrogen storage system comprises a compressor and a chiller that is coupled to at least one storage vessel structured to contain hydrogen.
7. The apparatus of claim 1, wherein the hydrogen storage system comprises at least one storage vessel structured to contain hydrogen using solid state hydrogen storage technology, whereby hydrogen is reacted with a metal to form a metal hydride, and subsequently the metal hydride is heated to release the hydrogen.
8. The apparatus of claim 1, wherein the separator is used to store hypochlorite in solution with spent brine.
9. The apparatus of claim 1, comprising a hypochlorite storage to store hypochlorite in solution with spent brine.
10. The apparatus of claim 1, comprising a power generation module for receiving hydrogen fuel from the hydrogen storage system, and generating electrical power using fuel cells or through combustion.
11. The apparatus of claim 1, wherein the hydrogen storage system comprises a hydrogen purification subsystem that collects hydrogen from the hydrogen conduit, and separates the hydrogen from non-combustible gases.
12. The apparatus of claim 1, where the electrolyzer comprises at least one dedicated electrolyzer solely for the production of hydrogen.
13. The apparatus of claim 1, where the hydrogen transfer device comprises a fueling device coupled to the hydrogen storage system for fueling a vehicle with hydrogen.
14. The apparatus of claim 1, where the hydrogen transfer device is designed to couple to a hydrogen storage tank on a vehicle for transportation of the hydrogen to another location.
15. A method for producing hypochlorite and hydrogen comprising the steps of:
- a. producing hypochlorite and hydrogen in an electrolyzer from brine received from a source of brine, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine;
- b. separating in a separator spent brine and hypochlorite in solution, and generated hydrogen received from the electrolyzer;
- c. directing generated hypochlorite from the separator to a hypochlorite storage,
- d. directing generated hydrogen from the separator to a hydrogen storage, and
- e. filling a storage tank in or on a vehicle with hydrogen from the hydrogen storage.
16. A distribution network for production, storage, and dispensing hydrogen gas, comprising:
- a. a plurality of water treatment devices, each device having: i. an electrolyzer that generates hypochlorite and hydrogen, which received brine from a source of brine, and, using electricity from a source of electrical energy, evolves hydrogen and hypochlorite from the brine by passing a electrical current through the brine; ii. a separator that receives the hypochlorite in solution with spent brine and generated hydrogen from the electrolyzer, and separates spent brine in solution with hypochlorite from hydrogen; iii. a hydrogen conduit coupled to the separator that transports hydrogen separated by the separator to a hydrogen storage system; and iv. a hydrogen transfer device coupled to the hydrogen storage system for transferring hydrogen from the hydrogen storage system;
- wherein the hydrogen transfer device is designed to transfer hydrogen from the hydrogen storage system to a storage tank in or on a vehicle;
- wherein at least one of the water treatment devices is located at a first water or waste water treatment facility; and
- wherein at least one of the water treatment devices is located at a second water or waste water treatment facility located a distance away from the first water or waste water treatment facility.
Type: Application
Filed: Dec 11, 2006
Publication Date: Apr 19, 2007
Inventor: Edward Fleming (Toronto)
Application Number: 11/637,468
International Classification: C25B 15/00 (20060101);