Abstract: Electrodes for an alkaline fuel cell are disclosed. The electrodes include a porous substrate and a catalyst layer supported on the substrate. The catalyst layer includes catalyst particles for catalyzing the electrochemical reaction occurring at the electrode, a hydrophobic binder for providing a network of hydrophobic gas passages communicating with the catalyst particles and hydrophilic catalytically inactive particles for providing a network of liquid transport pathways through the catalyst layer. The liquid transport pathways improve liquid transport through the catalyst layer and electrodes of the present invention provide improved resistance to electrode flooding and electrolyte pumping.

Abstract: The reactant manifolds and corners of a molten carbonate fuel cell stack are sealed with particulate lithium aluminate members which are sufficiently porous so as to resist significant electrolyte migration therethrough. The seal members which are disposed in vertical planes of the stack are preferentially formed from lithium aluminate grains which are bonded together by a silica-free glass binder. The seal members which are disposed in horizontal planes in the stack are preferably formed from lithium aluminate grains which are bonded together by surface hydrolysis. Alumina-clad stainless steel labyrinth seal members are associated with each of the horizontal seal members to inhibit electrolyte migration from the cell electrolyte matrices to the vertical seal members.

Abstract: The fuel gas reformer of a fuel cell power plant is provided with burner gas flow baffles which are annular in configuration, and which are concentric with the axis of the burner tube. The annular burner gas flow baffles form annular burner gas flow passages. The reformer has a plurality of annular arrays of catalyst filled tubes disposed in concentric rings about the burner tube. Each of the adjacent catalyst tube rings is separated from the next filled tube ring by one of the annular baffles. Burner gases are deflected downwardly and outwardly by the reformer housing top piece onto the catalyst filled tube rings. The baffles prevent inward flow of the burner gases and direct the burner gases uniformly downwardly along the catalyst filled tubes. Each ring of catalyst filled tubes is thus properly heated so as to enhance reforming of the fuel gas reactant.

Abstract: The electrolyte matrix and electrolyte reservoir plates in a molten carbonate fuel cell power plant stack are filled with electrolyte by applying a paste of dry electrolyte powder entrained in a dissipatable carrier to the reactant flow channels in the current collector plate. The stack plates are preformed and solidified to final operating condition so that they are self sustaining and can be disposed one atop the other to form the power plant stack. Packing the reactant flow channels with the electrolyte paste allows the use of thinner electrode plates, particularly on the anode side of the cells. The use of the packed electrolyte paste provides sufficient electrolyte to fill the matrix and to entrain excess electrolyte in the electrode plates, which also serve as excess electrolyte reservoirs. When the stack is heated up to operating temperatures, the electrolyte in the paste melts, the carrier vaporizes, or chemically decomposes, and the melted electrolyte is absorbed into the matrix and electrode plates.

Abstract: The anodes of fuel cells in a fuel cell stack are passivated during no load, hot-hold periods by directing a stream of desulfurized natural gas through the anode side of the cells in the stack. The cell voltage is thus maintained below 800 millivolts, preferably between 300 and 500 millivolts, during such periods.

Abstract: An electrolyte reservoir plate is formed in a papermaking process. Graphite powder, reinforcing fibers, cellulosic fibers, and a thermosetting resin are mixed with a liquid to form a slurry and showered onto a screen to form a planar sheet which is dried to form paper. The paper is cut into the desired size and is lay-up with main sheets 4 and edge strips 6. The lay-up is laminated with pressure and heat, carbonized, and graphitized to form an electrolyte reservoir plate.

Abstract: A flowable substance is applied to at least one predetermined area of a major surface of a plate-shaped fuel cell component by directing at least one stream of the flowable substance toward a predetermined zone that is situated in a plane along which the major surface of the component extends, facing the stream. The size of the predetermined zone is smaller than that of the predetermined area, and relative movement along the plane is effected between the component and the predetermined zone so that at least the entire predetermined area of the major surface gradually advances through the predetermined zone in a predetermined advancement direction and path. The stream is controlled so that it is in existence only while the zone is completely within the predetermined area, and until the zone has coincided with all of the predetermined area.

Abstract: A flowable substance is applied to at least one predetermined area of a major surface of a plate-shaped fuel cell component by directing at least one stream of the flowable substance toward a predetermined zone that is situated in a plane along which the major surface of the component extends, facing the stream. The size of the predetermined zone is smaller than that of the predetermined area, and relative movement along the plane is effected between the component and the predetermined zone in such a manner that at least the entire predetermined area of the major surface gradually advances through the predetermined zone in a predetermined advancement direction and path. The stream is controlled in such a manner that it is in existence only while the zone is completely within the predetermined area, and until the zone has coincided with all of the predetermined area.

Abstract: A fuel cell power plant in which the fuel cell stack is enclosed within a containment vessel and in which reformer burner exhaust is used to pressurize and purge the containment vessel is disclosed. The fuel cell power plant provides dynamic pressure balancing between the purge gas and fuel cell reactants to prevent leakage of the reactants from the fuel cell yet avoid an excessive pressure differential between the fuel cell and the containment vessel.

Abstract: High-purity nitrogen gas is generated by reducing at least the residual oxygen content of at least the cathode exhaust gas stream of a fuel cell device. The oxygen reduction is achieved either by controlling the passage of an oxidant gas through the cathode side of the fuel cell device in such a manner as to increase the oxygen utilization at the cathode side of the fuel cell device relative to the optimum electric power generation operating conditions of the fuel cell device, or by removing most of the residual oxygen from the cathode exhaust gas stream exhausted from the cathode side of the fuel cell device, while maintaining both oxygen and nitrogen contained in the cathode exhaust gas in their gaseous states throughout, or both. Moreover, anode exhaust gas can be reacted in a reformer burner with a reduced amount of excess oxygen and/or the reformer burner exhaust gas can be purified to remove combustion products and/or oxygen therefrom.

Abstract: The concentration of carbon monoxide in a gaseous medium is reduced by selective catalytic oxidation in the presence of gaseous oxygen by passing the gaseous medium through a catalyst capable of oxidizing carbon monoxide in an exothermic reaction at temperatures within a given temperature range and by controlling the temperatures encountered in the catalyst in such a manner that the exothermic reaction takes place first above a threshold temperature below which the catalyst would be rapidly inactivated at the relatively high carbon monoxide concentrations present in the gaseous medium as it enters the catalyst, and subsequently, after the carbon monoxide concentration has been reduced to an acceptable level, at less than the threshold temperature to further reduce the carbon monoxide concentration to a desired minimum level below that achievable at temperatures above the threshold temperature.

Abstract: A composite plate-shaped fuel cell component includes two electrically conductive porous plates juxtaposed and in area electrical contact with one another at an interface, and a sealant body accommodated in and completely filling the pores of a sealed region of each of the porous plates that extends to a predetermined distance from the interface into the respective porous plate to form a fluid impermeable barrier between the porous plates and to bond the porous plates to one another at the interface. The sealant body includes at least one layer of a fluoroelastomer sealant that fills all of the pores of at least one of the sealed regions.

Abstract: Sulfur compounds poison catalysts, such as the anode catalysts and reformer catalysts within molten carbonate fuel cell systems. This poisoning is eliminated using a sulfur scrubber 29 located prior to the inlet of the cathode chamber 13. Anode exhaust 19 which contains water, carbon dioxide and possibly sulfur impurities, is combined with a cathode exhaust recycle stream 22 and an oxidant stream 25 and burned in a burner 33 to produce water, carbon dioxide. If sulfur compounds are present in either the anode exhaust, cathode exhaust stream, or oxidant stream, sulfur trioxide and sulfur dioxide are produced. The combined oxidant-combustion stream 27 from the burner 33 is then directed through a sulfur scrubber 29 prior to entering the cathode chamber 13. The sulfur scrubber 29 absorbs sulfur compounds from the combined oxidant-combustion stream 27. Removal of the sulfur compounds at this point prevents concentration of the sulfur in the molten carbonate fuel cell system.

Abstract: An electrolyte reservoir plate is formed in a papermaking process. Graphite powder, reinforcing fibers, cellulosic fibers, and a thermosetting resin are mixed with a liquid to form a slurry and showered onto a screen to form a planar sheet which is dried to form paper. The paper is cut into the desired size and is lay-up with main sheets 4 and edge strips 6. The lay-up is laminated with pressure and heat, carbonized, and graphitized to form an electrolyte reservoir plate.

Abstract: Adjustment of the noble metal catalytic activity in the production of noble metal alloyed catalyst preparation using alloying metals capable of multiple valence states improves the alloying metal loading. A noble metal is precipitated from a liquid onto a support. Prior to the addition of an alloying metal which is capable of a low valence state having low solubility and a high valence state having high solubility, the catalytic activity of the noble metal precipitate is reduced. Reduction is accomplished by adjusting the temperature and/or pH of the liquid such that a minimal amount of the alloying metal will be converted from the lower to the higher valence state. By maintaining the alloying metal in the lower valence state, a greater amount of the alloying metal which has been dissolved into the liquid is precipitated onto the support, thereby attaining high loadings, reducing waste of the alloying metal, making the loadings predictable, and making the waste liquid more environmentally sound.

Abstract: A gas fired reformer includes a plurality of bayonet type reformers, each having a vertical outlet tube posted on a common outlet header. Three outlet header continuation members pass downwardly through the reformer shell to a ground support, at least one of these being a reformer gas outlet line.

Abstract: A carbon-based material substrate of a cathode electrode of an acid electrolyte fuel cell is made corrosion resistant by depositing a material that is nonwettable by the electrolyte on that major surface of the substrate which carries a catalyst layer all over except for its edge regions to cover such major surface at least at one of those of its edge regions which are exposed to an oxidizing gas during the operation of the fuel cell, but advantageously also at an additional one of its edge regions that is remote from the one edge region but is also exposed to an oxidizing gas during the operation of the fuel cell. The corrosion resistance can be further improved by extending the catalyst layer of the anode electrode on all sides beyond the cathode catalyst layer.

Abstract: Electrolyte migrates inter-cell in fuel cell stacks due to an electric potential gradient across the stack. This migration can be substantially inhibited with a graphite separator plate which has been laminated to the electrolyte reservoir plates of adjacent fuel cells with a fluoropolymer resin. In such an arrangement, the fluoropolymer resin forms an electrolyte barrier between the graphite separator plate while maintaining an electrically conductive pathway between the electrolyte reservoir plate and the graphite separator plate.

Abstract: A support plate for a proton exchange membrane fuel cell includes a porous support body that has a central portion and a peripheral portion integral with and circumferentially completely surrounding the central portion, and a sealing body of elastomeric sealing material that completely fills the pores of the peripheral portion to make it impermeable to fluids. The support plate may be assembled with another one and with a proton exchange membrane interposed between the two support plates to form an assembly, and the sealing body then peripherally joins and seals the assembly and fills any gaps that may be present between the peripheral portions due to the absence of the membrane from such regions and thus to peripherally encapsulate the membrane.

Abstract: An electrochemical sensor comprised of wires, a sheath, and a conduit can be utilized to monitor fuel cell component electric potentials during fuel cell shut down or steady state. The electrochemical sensor contacts an electrolyte reservoir plate such that the conduit wicks electrolyte through capillary action to the wires to provide water necessary for the electrolysis reaction which occurs thereon. A voltage is applied across the wires of the electrochemical sensor until hydrogen evolution occurs at the surface of one of the wires, thereby forming a hydrogen reference electrode. The voltage of the fuel cell component is then determined with relation to the hydrogen reference electrode.