Patent Publication Number: US-2002006533-A1

Title: Hydrogen gas generator

Description:
RELATED APPLICATION  
     [0001] This application claims priority of my co-pending U.S. Provisional Patent Application No. 60/209,543 filed Jun. 6, 2000, the disclosure of which is hereby incorporated by reference. 
    
    
     
       SPECIFICATION  
       Background of the Invention  
       [0002] 1. Field  
       [0003] The invention relates to fuel cells, and more specifically to the production of hydrogen to power fuel cells.  
       [0004] 2. State of the Art  
       [0005] There are many people in today&#39;s world that are involved in developing alternative energy sources and are currently involved in research to develop efficient, economical sources for the gas hydrogen. While it has been determined from research that petroleum will continue to fill a strong role with the major share of the market in the field of plastics and lubricants, hydrogen will eventually become the sole source for fuel for the  21 st century. Petroleum, or hydrocarbons, and byproducts thereof are the source for ninty-six percent of the pollution in the world today. Conversely, hydrogen is recyclable and non-polluting.  
       [0006] Hydrogen as a fuel has been the energy dream of a generation of scientists around the world as a permanent solution for global energy. Why are they looking at hydrogen as the world wide energy solution? Over ninety-eight percent of the matter in the universe is hydrogen. Over two-thirds of the surface of the earth is water, which is two parts of hydrogen for every one part of oxygen. One of the most efficient, effective ways of producing electrical power is in an electrochemical engine, or fuel cell, of which the most effective are powered by hydrogen.  
       [0007] Water, because its components are oxygen and hydrogen is the most dense energy source known to man. Researchers have been trying for years to find the secret to breaking water economically into oxygen to support combustion and hydrogen as the combustible material.  
       [0008] Fuel cells are not new. Their non-polluting qualities and efficient delivery of electrical power have been known for some time. Our Space program depends on fuel cells. But, there are drawbacks to the present method of fueling the fuel cell which have made commercial production for the general public not feasible. There are four major types of fuel cells currently in-use or under development: 1)Proton Exchange Membrane Fuel Cell (PEM); 2)Alkaline Fuel Cell; 3) Solid Oxide Fuel Cell; and 4)Phosphoric Acid Fuel Cell.  
       [0009] Research has identified three major problems that need to be solved to make any of the above fuel cells a reality for use by the general population of the world. The first problem is the delivery of hydrogen to the fuel cell. All fuel cells require hydrogen in one form or another for fuel. The only method that we now have for producing hydrogen is at a large fixed facility which produces compressed hydrogen at about 3,000 pounds per square inch for transportation to the point of consumption. Hydrogen is extremely dangerous in large compressed quantities and very expensive to transport in pressurized cylinders. For instance, to transport hydrogen in pressurized tanks, it requires an eighty-thousand pound eighteen-wheel tractor trailer to transport only six hundred pounds of hydrogen. The second problem is that the most promising fuel cell, the Alkaline Fuel Cell which our space program depends on, begins to lose its ability to produce electrical energy over time if the air supply to it supplying the oxygen for reaction with the hydrogen contains carbon dioxide. The third problem is the fuel cell that most developers are spending their research funds developing, the Proton Exchange Membrane Fuel Cell, is extremely expensive to manufacture and requires frequent and extensive maintenance and cannot be operated at temperatures below freezing without special heating devices. The National Aeronautics and Space Administration (NASA) stopped using PEM fuel cells in the nineteen-sixties and went solely to the Alkaline Fuel Cell for power in its space program. The PEM Fuel Cell was rejected by NASA as it did not function nearly as efficiently as the Alkaline Fuel Cell and was not dependable in space, where most mechanical devices are unmanned and most function without maintenance.  
       [0010] In my co-pending U.S. patent application Ser. No. 09/656,729 filed Sep. 7, 2000 is disclosed more background information about fuel cells, the disclosure of which patent application is hereby incorporated by reference.  
       [0011] There is a need for a hydrogen gas generator for use in a system for producing electrical energy also utilizing a fuel cell, which hydrogen gas generator releases hydrogen from ordinary water to form a non-polluting totally recyclable system.  
       SUMMARY OF THE INVENTION  
       [0012] The present invention comprises a hydrogen gas generator, an electrical power generation system, and supply tube assembly.  
       [0013] The hydrogen gas generator is for producing hydrogen gas from the controlled reaction of an alkaline metal contained in a supply tube assembly which is introduced in incremental amounts to water within a contained space. The hydrogen gas generator comprises a sealable pressure tank for holding the water into which the alkaline metal is to be introduced and for holding hydrogen gas produced by the chemical reaction between the alkaline metal and the water. The pressure tank further includes at least one sealable opening for introducing water and outletting hydrogen gas, and an alkaline metal introduction system comprising a pump operably connected to the tank and adapted to feed incremental amounts of the alkaline metal from the supply tube assembly into the pressure tank while the tank remains substantially sealed from ambient air, and without significant loss of hydrogen pressure therein.  
       [0014] The electrical power generation system comprises the hydrogen gas generator as described, and a fuel cell operatively connected to the hydrogen gas generator for receiving hydrogen from the pressure tank and carbon dioxide free air bubbled through sodium hydroxide produced in the pressure tank to produce electricity.  
       [0015] The supply tube assembly is for dispensing incremental amounts of a material contained therein comprising an outer tube made of a substantially resilient material which is substantially non-reactive with one or more alkaline metals. The said outer tube is sealed at one end thereof and sealable at an opposite end thereof. The material comprises an alkaline metal which is substantially non-reactive with the material from which the outer tube is made. The alkaline metal is contained within the outer tube between the ends thereof. 
     
    
    
     THE DRAWINGS  
     [0016]FIG. 1, a schematic side elevational view of a hydrogen gas generator according to the present invention; and  
     [0017]FIG. 2, a schematic top plan view of the hydrogen generator. 
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS  
     [0018] A hydrogen gas generator constructed in accordance with the invention is shown schematically in FIGS. 1 and 2, generally designated  20 . Generator  20  comprises an alkaline metal introduction system  23  which is mounted to a pressure tank  26 .  
     [0019] Pressure tank  26  is of generally cylindrical configuration, including a cylindrical body  29  and respective end caps  32  and  35 . A mounting bracket  38  is affixed to an upper portion  41  of body  29 , and a pair of ground-contacting stabilizing brackets  44  are affixed to a lower portion  47  of body  29 . Tank  26  further includes a threaded fitting  50  and a tube adapter fitting  53  that are affixed to upper portion  41 , both of which communicate with an inner chamber  56  of tank  26 . A hose attachable valve  57  with an attached pressure indicator  58  is threadably connected to fitting  50 . Alkaline metal introduction system  23  includes a support frame  59  having a pair of vertically disposed parallel plates  62  and  65  which bolt to mounting bracket  38 . A plurality of spacers and bolts (not shown) maintain plates  62  and  65  in a spaced parallel relationship.  
     [0020] Alkaline metal introduction system  23  further includes a peristaltic pump  68 . Pump  68  comprises a disk  74  having an annular peripheral groove  77  into which a plurality of rollers  80  are rotationally disposed, with respective outer surfaces  83  thereof which extend radially beyond an outermost peripheral surface  86  of disk  74 . Disk  74  is rotationally mounted to support frame  59  between plates  62  and  65  by means of a main drive shaft  89  rotationally keyed thereto and supported by plates  62  and  65  on a pair of ball bearings (not shown). Pump  68  further includes semi-arcuate compression ring  92  which is pivotally mounted to support frame  59  between plates  62  and  65  on a pivot pin  95 . An inner surface  98  of ring  92  is of a corresponding radius to that formed by the respective outer surfaces  83  of rollers  80 . A pump lever  96  is pivotally mounted to support frame  59  between plates  62  and  65  on a pivot pin  101 . Pump lever  96  is positioned so as to apply a radially inwardly directed force to ring  92  when a downwardly directed force is applied by hand to a gripping portion  104  of pump lever  96  opposite pivot pin  101 .  
     [0021] Alkaline metal introduction system  23  further includes a pump drive assembly  107 , which has a driven sprocket  110  keyed to main drive shaft  89  outside of plate  65 . A secondary drive shaft  113  is rotationally mounted to support frame  59 , being supported by plates  62  and  65  on a pair of ball bearings (not shown). A drive sprocket  116  of smaller diameter than driven sprocket  110 , and a hand crank  119  are keyed to secondary drive shaft  113  outside of plate  65 . The respective drive and driven sprockets  116  and  110  are rotationally coupled together by a drive chain  122  such that rotation of the hand crank  119  rotates disk  74 .  
     [0022] Alkaline metal introduction system  23  further includes a tube retaining assembly  125 , which has a tube retention lever  126  pivotally mounted to support frame  59  between plates  62  and  65  on a pivot pin  128 . Tube retention lever  126  is positioned so as to apply a much greater inwardly directed force at a cam locking portion  131  adjacent pivot pin  128  when an inwardly directed force is applied by hand to a gripping portion  134  of tube retention lever  126  opposite pivot pin  128 . A backing plate  137  of support frame  59  is affixed between  62  and  65 , backing plate  137  having a tube support surface  140  which is slightly spaced from a lower locking surface  143  of cam locking portion  131  when tube retention lever  126  is in an unlocking position. Cam locking portion  131  is configured relative to pivot pin  128  so as to retain tube retention lever  126  in a locked position when an object (not shown) is gripped between the respective surfaces  140  and  143  and an inwardly directed force is applied by hand to gripping portion  134 . A return spring  146  is connected between cam locking portion  131  and support frame  59  to bias tube retention lever  126  to the unlocking position for ease of inserting the object to be gripped.  
     [0023] The hydrogen gas generator  20  uses supply tube assemblies  149  containing an alkaline metal to fuel the generator  20 . Tube assemblies  149  include an outer tube  152  is made of a resilient plastic such as nylon, polypropylene, etc., or made of another such resilient material which is non-reactive with alkaline metals. The outer tube  152  is filled with an alkaline metal  155 , being retained within tube  152  by an end seal comprising an end plug  158  having an externally threaded body  161  adapted to tightly thread into an inner bore  164  through outer tube  152  at an open end  167  opposite a sealed end  170  of outer tube  152 , to provide an airtight seal to shield the alkaline metal  155  within outer tube  152  from being exposed to the ambient air. The end plug  158  further includes an integral gripping tab  173  which aids in twisting plug  158  during insertion and subsequent removal from outer tube  152  prior to use in generator  20 .  
     [0024] The Hydrogen Gas Generator  20  develops hydrogen gas from water through a chemical reaction resulting from combining the alkaline metal  155  with water (not shown) contained within the pressure tank  26 . The chemical reaction is controlled by only allowing measured amounts of the alkaline metal  155  to be placed into the water, such as at specific intervals, to maintain a predetermined pressure within tank  26 . For example, dispensing alkaline metal  155  into tank  26  of a seven gallon size which holds five gallons of water, a pressure of about 17 PSI is achieved by the produced hydrogen gas.  
     [0025] The hydrogen gas generator  20  is prepared for producing hydrogen gas by first filling tank  26  with water by removing valve  57 , adding the appropriate measured amount of water to fill tank  26  to about eighty percent of its capacity, and replacing valve  57 . Alternatively, separate filling and/or draining openings and mating plugs or valves (not shown) can be provided on tank  26  to facilitate filling and draining. Next, pump lever  96  is pivoted upwardly releasing compression ring  92  to be pivoted upwardly. Tube retention lever  126  lever is then moved outwardly. One supply tube assembly  149  is assembled to generator  20  following the unscrewing and removal of end plug  158  from open end  167 , which is fit over adapter fitting  53  of tank  26 , being held in position using a hose clamp (not shown) or other suitable clamping device. Closed end  170  of outer tube  152  is disposed under locking cam portion  131  of tube retention lever  126 , outer tube  152  lying along tube support surface  140  of backing plate  137  and over rollers  80  of pump  68 . Tube retention lever  126  is then moved inwardly to pinch closed end  170  of outertube  152  between locking cam portion  131  and tube support surface  140  of backing plate  137 . This applies about eighty pounds per square inch of pressure to closed end  170  of outer tube  152  providing a secure hold thereof. Next, compression ring  92  is pivoted downwardly onto outer tube  152  and pump lever  96  is pivoted downwardly into contact with compression ring  92 .  
     [0026] The hydrogen gas generator  20  is now ready to dispense the alkaline metal  155  contained in the supply tube assembly  149  into the tank  26 . This is accomplished by rotating hand crank  119  a predetermined rotational distance while maintaining a predetermined pressure on the gripping portion  104  of pump lever  96 . This causes  74  to move rollers  80  against outer tube  152  to force a predetermined quantity or a single “charge” of the alkaline metal  155  contained between rollers  80  through tube adapter fitting  53  into the water contained within the tank  26  based on design factors of the pump  68  such as the size and spacing of the rollers  80 . The instant the charge of the alkaline metal  155  is released into the water contained within tank  26 , a chemical reaction takes place wherein the alkaline metal  155  combines with the water to chemically release one hydrogen from the two contained in each molecule of the water. The released hydrogen gas is contained in the portion of inner chamber  56  not occupied by the water until it is released for use as an energy source through a hose (not shown) attached to valve  57 .  
     [0027] More hydrogen gas can be produced by rotating the hand crank  119  as needed until all the alkaline metal  155  is used up that was contained in the supply tube assembly  149 , or until the hydrogen production capability of the water has been depleted. In the former case, the empty supply tube assembly  155  is replaced with a full one. In the latter case, the remaining hydrogen gas is used up or exhausted to atmosphere and the depleted water replaced with fresh water.  
     [0028] The principle that makes the hydrogen gas generator function is the well-known chemical reaction which results from putting an alkaline metal such as sodium into water. The very instant that sodium is released into water an immediate chemical reaction takes place. The sodium combines with one hydrogen and one oxygen releasing one hydrogen (Na plus H 2 0 equals NaOH and H).  
     [0029] The NaOH, or sodium hydroxide, part of the chemical reaction can be used to strip carbon dioxide form the ambient air by simply bubbling the air through the sodium hydroxide solution. The H, or hydrogen, part of the reaction can be used to fuel a fuel cell or any device that uses combustible gases for power.  
     [0030] The hydrogen gas generator  20  is an improvement over the existing hydrogen generation devices as it allows the instant explosive nature of the chemical reaction between an alkaline metal and water to be controlled and contain. The by-products of the reaction are hydrogen, and in the case where sodium is the alkaline metal, sodium hydroxide, both being contained in a pressure vessel to be used as they are required. The generator allows the instant explosive nature of the chemical reaction between an alkaline metal and water to be conducted in a safe efficient closed container, wherein the operator is totally insulated from the chemical reaction. The generator allows the instant explosive nature of the chemical reaction between an alkaline metal and water to be conducted on a limited and controlled basis to only produce the amount of hydrogen gas that is required at any given time. The generator allows the instant explosive nature of the chemical reaction between an alkaline metal and water to be conducted on an as-needed basis, so that there is only a safe predetermined amount of hydrogen gas in the pressure vessel at any given moment. The generator allows hydrogen to be transported in its most dense form, that of water, and to be produced at the location that it is required and in the amounts that are required at any given moment. The generator is an improvement over any prior art in the field as it is a unique device that produces the gas hydrogen in a totally safe environment as it is required, in only the quantities that are required at any particular time from water, and it light-weight, compact, and portable.  
     [0031] The hydrogen gas generator solves the three problems described above by using ordinary water which covers most of the earth&#39;s surface, and which is the most energy dense medium for transporting hydrogen. Hydrogen can now be supplied at the point that it is needed, as it is needed, by simply chemically breaking down water into hydrogen and oxygen. The consumer fills the tank with water and by the timed and measured addition of a non-polluting chemical, the water molecules each release one of two hydrogen atoms, producing the hydrogen gas needed to fuel a fuel cell such as an alkaline fuel cell. This solves the first problem of transporting hydrogen at high pressure, since hydrogen can be produced from water as it is needed at the point of consumption. The second problem is solved simply by utilizing the by-product of the hydrogen gas generator, which is sodium hydroxide, to clean the incoming air to the fuel cell. Carbon dioxide has a high affinity to combine with sodium hydroxide. The sodium hydroxide is created by the alkaline metal, sodium, combining with the water, creating the perfect scrubber for the stripping of the carbon dioxide from the incoming air to the fuel cell. The solution to the third problem disappears with the solving of the first two problems, as the resulting hydrogen gas generator and the alkaline fuel cell is cost effective, eliminating the need for the expensive Proton Exchange Membrane Fuel Cell Fuel Cell.  
     [0032] The hydrogen gas generator enable industry to manufacture a complete electrical producing plant. The primary electrical plant will consist of an alkaline fuel cell coupled to the hydrogen gas generator that will also, by using the by-product of the chemical reaction, strip the in-coming air to the fuel cell of carbon dioxide. These plants could be sold in different sizes, from one kilowatt to many mega-kilowatts, depending on what is needed by the consumer. A plant of the proper kilowatt size could be used for tools as small as lawn mowers to units large enough to produce energy for whole cities.  
     [0033] Many variations of the hydrogen gas generator are possible while staying within the same inventive concept. For example, while the generator is shown as a portable unit, it could be a larger, fixed unit such as for supplying hydrogen to a fuel cell which generates electricity for a house or an office building. Many different types of tanks can be used, which might be separate from the pump. Other types of pumps can be used which provide incremental depositing of the alkaline metal into the water for a controlled reaction and production of hydrogen gas.  
     [0034] Whereas this invention is here illustrated and described with reference to embodiments thereof presently contemplated as the best mode of carrying out such invention in actual practice, it is to be understood that various changes may be made in adapting the invention to different embodiments without departing from the broader inventive concepts disclosed herein and comprehended by the claims that follow.