Electrochemical conversion system

#This invention relates to the conversion of heat energy into electrical energy utilizing a hydrogen electrochemical cell.

#The conversion of chemical energy to electrical energy may be accomplished in a variety of ways. It is known that electrochemical cells or batteries rely on redox reactions wherein electrons from reactant being oxidized are transferred to a reactant being reduced. With the separation of the reactants from each other, it is possible to cause the electrons to flow through an external circuit where they can be used to perform work.

#Electrochemical cells however have had a problem related to the exhaustion of the reactants. Although most cells can be recharged by applying a reverse polarity voltage across the electrodes, such recharging requires a separate electrical source. During the recharging of the cell the cell typically is not utilized as an electrical power source, thus rendering it unusable during the recharging period.

#FIG. 1 is a schematic view of an electrochemical conversion system in a preferred form of the invention.

#FIG. 2 is a schematic view of an electrochemical conversion system in another preferred form of the invention.

#FIG. 3 is a schematic view of an electrochemical conversion system in another preferred form of the invention.

#With reference next to the drawings, there is shown in FIG. 1 an electrochemical conversion system 10 in a preferred form of the invention. The system 10 has a housing 11 made of a non-reactive metal, such as stainless steel, in which is mounted an electrochemical or hydrogen concentration cell 12. The combination of the housing 11 and the concentration cell 12 define a first chamber 13 and a second chamber 14 separated from each other by the concentration cell 12. A first mass of hydride material 17, such as LaNi4.7Al0.3, TiFe0.9Mn0.1, liquid hydride, or other similar material, is contained within the first chamber 13. Similarly, a second mass of hydride material 18 is contained within the second chamber 14. For liquid hydride materials the terms hydride, metal hydride, hydrogen absorbent material and hydrogen absorbent metal material are equivalent.

#The electrochemical cell 12 has a first gas diffusion electrode 20, a second gas diffusion electrode 21 and a proton conductive membrane 22, such as an perfluorinated polymer ionomer as for example Nafion made by13E. I du Pont de Nemours, mounted between the first and second gas diffusion electrodes. This type of electrochemical cell 12 is available from E-Tek, Inc. of Somerset, N.J. The electrochemical cell electrodes 20 and 21 are electrically coupled to an external load or circuit 23.

#The system 10 also includes all alternating heat transfer system 25 which selectively transfers heat to one mass of metal hydride material while absorbing heat from the other mass of metal hydride material. The heat transfer system 25 may utilize any form of heat source such as electric heaters, gas burning heaters, heated air, radiation heat sources, radiant heaters or other conventionally known means for producing heat. The heat transfer system 25 may also utilize any form of heat absorbing or dissipating means (heat sink), such as cooled fluids.