Hydrogen generating system

Abstract

A hydrogen generator comprises a U-tube electrolysis unit, the hydrogen being produced in one side and oxygen in the other. The hydrogen is passed from the unit through filter chambers for preventing the final discharge of acid or of water and the hydrogen is stored in a tank containing lanthanum-nickel alloy for increasing the storage capacity.

Description

My invention relates to hydrogen gas generators and particularly to an improved hydrogen generator for storing the gas at relatively low pressures.

The production of hydrogen gas by the electrolysis of water is well known and many designs of apparatus have been provided for this purpose. The use of hydrogen for the production of heat by combustion is attractive from the standpoint of minimizing atmospheric pollution, the product of combustion being pure water vapor. The storage of hydrogen involves the problems of high pressure gas storage and it is desirable to store the gas at as low a pressure as can be used while storing sufficient gas in an economical manner and in quantities sufficient for relatively long periods of time. Accordingly, it is an object of my invention to provide an improved system for the economical generation and storage of hydrogen gas.

It is another object of my invention to provide a hydrogen gas generating system including a new and improved arrangement for storing the generated gas in preparation for use.

Briefly, in carrying out the objects of my invention in one embodiment thereof, an electrolysis unit of the U-tube type is connected to discharge hydrogen to cleaning equipment for removing acid and water and thence to a storage chamber. The water input to the electrolysis unit is controlled by a float valve on the oxygen side of the unit and the discharge of hydrogen is shut off by a float valve or a predetermined rise of water in the hydrogen side. Acid is prevented from reaching the storage tank by a mass of zinc particles in a first cleaning stage and water is trapped by a mass of granular calcium chloride in a second cleaning stage. The hydrogen is stored in a reservoir at pressure dependent upon the supply pressure of the water at the electrolysis unit. The storage reservoir is charged with a quantity of lanthanum-nickel which absorbs hydrogen without chemical change and greatly increases the storage capacity of the reservoir.

The features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. My invention itself, however, both as to its organization and its method of operation together with other objects and advantages thereof, will best be understood upon reference to the following description taken in connection with the accompanying drawing in which the single FIGURE represents diagrammatically a hydrogen gas generator embodying my invention.

The drawing illustrates a sealed hydrogen generating and storage system. This system includes a hydrogen generator comprising a U-tube electrolysis unit 10 arranged to receive water through an inlet 11 under control of an automatic pressure regulating valve 12 and to deliver it to the U-tube under control of a float valve 13. The valve element, which is indicated diagrammatically, is preferably of the needle type for fine control and shut-off. The details of the valve are not shown as they are not essential to an understanding of the invention. The valve is actuated by a pair of floats, one on either side of an electrode 14 and connected by a yoke 15, only the near side float appearing in the drawing as indicated at 16. The electrode 14 extends through a sealed top cap 17 from which it is insulated by a bushing 18 of a suitable insulating material. The water pressure at the valve inlet is indicated by a gauge 19 connected to the inlet 11. The other side of the U includes an electrode 20 mounted in a sealing cap 21 in an insulated bushing 22 and extending downwardly into the right hand leg of the U. The liquid in the U-tube is a suitable electrolyte and in the present system may be a dilute solution of sulphuric acid. Oxygen is generated in the left hand leg and hydrogen in the right hand leg when a current is passed between the electrodes 14 and 20, the electrode 14 being the anode and the electrode 20 the cathode. The anode 14 is preferably nickel plated and the cathode 20 is made of iron without plating. As the gases are produced by electrolysis in the generator 10, oxygen is removed for use or dissipated to the atmosphere from the left hand leg of the U-tube through the control valve of a gas pressure regulator 23. Hydrogen flows from the right hand leg through a conduit 24 and into an acid removing chamber 25. The chamber 25 is cylindrical and provided with a sealed top 26 secured by bolts 27 to a flange 28 at the top of the cylinder. The conduit 24 is provided with a flanged coupling 30 and manual shut-off valves 31 and 32 which are closed when the flange 30 is opened for servicing. A check valve 33 is provided in the conduit 24 between the flange 30 and the valve 31 for preventing back flow from the chamber 25 to the U-tube. In the event that the electrolyte rises sufficiently, a float controlled valve 34 is closed. This valve is controlled by a pair of floats similar to those of the valve 15, one on either side of the electrode 20, the near one of which appears at 35. The two floats are connected by a yoke 36 attached to the valve 34.

The conduit 24, the water inlet conduit 11 and a conduit 43 through which the oxygen is discharged, are all insulated from the outer metal wall of the U-tube in a manner similar to the insulation between the electrodes and the top caps 17 and 21. The insulation between the wall of the U-tube and the conduits is indicated at 44, 45 and 46 for the conduits 11, 24 and 43, respectively. The U-tube 10 comprises an outer metal wall 47 and a glass liner 47a.

Hydrogen gas flowing through the conduit 24 flows downwardly toward the bottom of the chamber 25, a screen or foraminous plate 37 being provided at the bottom and extending across the entire cross section of the chamber except for an opening accommodating the tube 24. The screen 37 slopes in all directions away from the outlet of the conduit 24a and supports a mass of zinc particles generally indicated at 38. The screen 37 prevents the particles from falling to the bottom of the chamber 25 and holds them in position so that all the gas which flows through the conduit 24 must flow up through the mass of zinc particles before it can be discharged from the chamber through the discharge outlet indicated at 40. In the event that excess water or electrolyte should be accumulated in the chamber 25 under unusual conditions of operation, a float 41 is arranged to close a valve 42 to prevent passage of the electrolyte into the conduit 40.

The hydrogen gas which has passed through the chamber 25 and out through the conduit 40 and its downwardly extending portion indicated at 40a within a second chamber 48, and flows upwardly in the chamber 48 from the bottom portion after passing through a screen or foraminous plate 50, and passes through a mass of granular calcium chloride 51 for the purpose of removing any water which may have reached the chamber 48. The two sections of the conduit 40 between the chambers 25 and 48 are joined by a detachable flanged coupling 52 and are provided with respective shut-off valves 53 and 54 for preventing the passage of gas in or out of the two chambers when the coupling is opened. The dry hydrogen gas passes out of the chamber 48 through a conduit 55 having therein a filter 56 and a shut-off valve 57. This gas flows through a detachable flanged coupling 58 and a shut-off valve 60 and thence downwardly through a conduit 61 to a storage tank 62. A safety or emergency float valve comprising a valve 63 and a float 64 is provided in the tank 48 to close the outlet in the event of flooding of the chamber 48. In the event of such emergency this prevents the admission of water to the storage tank 62. The storage tank 62 is provided with an outlet conduit 65 from the top thereof and the conduit is provided with a shut-off valve 66 and a filter 67. A supply conduit 68 for an appliance or other utilization device employing hydrogen is connected to the conduit 65 by a flanged coupling 70 and is provided with a manual shut-off valve 71. The pressure within the system as illustrated in the drawing is controlled by the pressure of the water entering the electrolysis unit 10 through the inlet 11. The system throughout is substantially at this pressure except for differences in pressure due to the flow of the hydrogen gas, and for differences in pressure due to the water levels in the U-tube. The combined action of the regulators 12 and 23 serves to control the pressure in the system and maintain it within selected limits. For example, with a water supply pressure at say fifty pounds per square inch, the regulators may be set to maintain a system pressure of the order of twenty-five pounds per square inch for the generation and storage of hydrogen. The pressure maintained in the system may be somewhat variable over a selected relatively narrow range in the neighborhood of twenty-five pounds per square inch during the operation of the system.

It is desirable to store large quantities of gas without requiring storage at high pressure and for this purpose I provide in the storage tank 62 a body of lanthanum-nickel alloy indicated at 72 and which is initially in the form of rods or bars as supplied by the manufacturer. At the present time this lanthanum-nickel alloy may be purchased from Molybdenum Company of America, White Plains, New York. Over the period of the operation of the system, lanthanum-nickel (La.sub.2 Ni.sub.5) disintegrates from its bar form and forms a mass of powdered material in the lower portion of the tank 62. This material will last as a storage means over a long period of time provided water and oxygen or other substances capable of reacting with the alloy are prevented from reaching it. The lanthanum-nickel alloy has the property of absorbing large amounts of hydrogen and the presence of the metal within the tank makes it possible to charge a substantially greater volume of gas within the tank than can be charged in the tank at the same pressure without the metal present. As a result, substantial amounts of hydrogen gas may be stored within the tank 62 for use as required by the utilization devices connected to the supply conduit 68. The electrolysis generator 10 may thus be run substantially continuously over long periods of time subject to shut-down in the event of long periods of non-use of a stored gas. The electrolysis operation is discontinued when the gas in the tank 62 reaches a predetermined pressure which forces the electrolyte in the U-tube down below the electrode 20 and which disconnects the electric circuit until the electrolyte again rises to contact the electrode, whereupon the generation of hydrogen is resumed.

The hydrogen generating system as disclosed has the advantage of providing a gas which is clean in that it burns without particulate residue, the product of combustion being pure water vapor.

The electricity for operation of the electrolysis generator may be supplied in any suitable manner and for many installations it is preferable to employ electrical generating means which do not require the combustion of ordinary fuels. Thus, water wheel generators, windmills and solar generators are suited for use in connection with this system. In all cases the electrolysis generation may be continued during the operation of the water wheel, windmill or solar generator to store substantial amounts of hydrogen during the active period of the power means, the hydrogen being available over extended periods due to the increased storage capability of the tank 62 when the generator is not in operation.

While I have illustrated a specific preferred arrangement of my hydrogen gas generating system, other applications and modifications will occur to those skilled in the art. Therefore, I do not desire my invention to be limited to the details of the system illustrated and I intend by the appended claims to cover all modifications which fall within the spirit and scope of my invention.

Claims

I claim:

1. A hydrogen gas generating and storage system comprising:

means utilizing the electrolysis of water for producing oxygen and hydrogen and including means providing zones for collecting and for discharging the two gases separately;

means for supplying water to said producing means and for maintaining a predetermined range of pressures in said system;

a reservoir for storing the hydrogen gas at the pressure maintained by said supplying means and connected to the hydrogen zone of said producing means;

a body of lanthanum-nickel in said reservoir for raising the storage capacity thereof; and,

means for withdrawing hydrogen from said reservoir for use.

2. A hydrogen gas generating and storage system as set forth in claim 1 including means connected between said producing means and said storage means for removing water from the hydrogen flowing to said storage reservoir.

3. A hydrogen gas generating and storage system as set forth in claim 1 including means for removing acid from the hydrogen flowing toward said reservoir.

4. A hydrogen gas generating and storage system as set forth in claim 1 including filtering and cleaning means for removing foreign matter from the hydrogen and disposed in a hydrogen conduit between said producing means and said reservoir means for supplying substantially pure hydrogen to said reservoir.

5. A hydrogen gas generating and storage system as set forth in claim 1 wherein said producing means is an electrolysis generator of the U-tube type wherein oxygen is generated in the water inlet leg of the U-tube and hydrogen in the other leg thereof and including a first float controlled valve for shutting the water supply on a predetermined rise of water in said inlet leg and a second float controlled valve for closing the hydrogen outlet of said producing means upon a predetermined rise of water in said other leg.

6. A hydrogen gas generating and storage system as set forth in claim 4 including two closed chambers connected in series in the hydrogen conduit between said producing means and said reservoir, one of said chambers having means for retaining a mass of acid removing material therein and having means for directing the flow of hydrogen from the lower portion upwardly through said mass, and the second of said chambers having a mass of dehydrating material therein and means for directing the hydrogen flowing therethrough upwardly through said mass.

7. A hydrogen gas generating and storage system as set forth in claim 1 including filter means connected in the discharge conduit of said reservoir for removing particulate matter from the hydrogen removed from said reservoir.

8. A hydrogen gas generating and storage system as set forth in claim 4 including detachable couplings in the hydrogen conduit between said producing means and said filtering and cleaning means and between said last mentioned means and said reservoir, and shut-off valves on each side of each of said couplings for preventing the loss of hydrogen to the atmosphere.

9. A hydrogen gas generating and storage system comprising:

means utilizing the electrolysis of water for producing oxygen and hydrogen including means providing respective separate zones for collecting the gases and means for discharging the separate gases;

means for supplying water under pressure to said producing means and utilizing the pressure of the water for maintaining a predetermined range of pressures in said system;

a closed reservoir connected to the hydrogen zone of said producing means for receiving the discharged gas for storage at the pressure maintained by said supplying means;

a body of metal alloy capable of absorbing large amounts of hydrogen gas at pressures of the order of twenty-five pounds arranged in said reservoir for raising the storage capacity thereof; and,

means for discharging hydrogen from said reservoir for use.

10. A hydrogen gas generating and storage system as set forth in claim 9 wherein said producing means is an electrolysis generator of the U-tube type wherein oxygen is generated in the water inlet leg of the U-tube and hydrogen in the other leg thereof and including a first float controlled valve for shutting the water supply on a predetermined rise of water in said inlet leg and a second float controlled valve for closing the hydrogen outlet of said producing means upon a predetermined rise of water in said other leg and wherein said separate zones lie in the upper portions of respective ones of said legs.