Abstract: An environmental compensation apparatus for an electrochemical fuel cell assembly, wherein a compressible material is dispersed within a coolant flow of the fuel cell assembly and is utilized to compensate for the expansion of the coolant when said fuel cell assembly is subjected to harsh environmental conditions. The compressible material is formed as a plurality of either polymeric or elastomer microspheres, each microsphere having a diameter larger than the pores of an anode or cathode flow field plate, yet smaller than the diameter of a coolant channel.

Abstract: A fuel gas reformer assemblage for use in a fuel cell power plant is formed from a composite plate assembly which includes spaced-apart divider plates with interposed monolithic open cell sponge-like members which form gas passages. The monolithic members have a lattice of internal open cells which are both laterally and longitudinally interconnected so as to provide for a diffuse gas flow. The entire surface area of the monolithic components is wash coated with a porous alumina layer, and selected areas of the wash coat are also catalyzed. The reformer assemblage is constructed from a series of repeating sub-assemblies, each of which includes a core of separate regenerator/heat exchanger gas passages. The core in each sub-assembly is sandwiched between a pair of reformer gas passage skins, which complete the subassembly. Adjacent reformer gas/regenerator/reformer gas passage sub-assemblies in the composite plate assembly are separated from each other by burner gas passages.

Abstract: The invention is a pressurized water recovery system for a fuel cell power plant including at least one fuel cell having an electrolyte between anode and cathode electrodes for producing an electric current from a reducing fluid and an oxidant stream. A coolant loop directs a coolant fluid from a reservoir through a coolant passage to the fuel cell and back to the reservoir, and the coolant loop also receives coolant fluid through water lines secured between condensing heat exchangers and the coolant reservoir. A process exhaust passage directs a process exhaust stream from adjacent the cathode and anode electrodes out of the fuel cell and into a condensing heat exchanger. Whenever the power plant is under coolant stress, a process exhaust valve selectively directs a portion of the process exhaust stream out of the process exhaust passage to a supercharger that pressurizes the received portion of the process exhaust stream and directs the pressurized portion to a pressurized condensing heat exchanger.

Abstract: A fuel cell stack includes a plurality of fuel cells, each of which includes a membrane electrode assembly and a water transport plate, or a fluid flow plate fabricated from graphite. This plate and optionally a separator plate are held in assembled relationship with one another and with the membrane electrode assemblies by a fluoroelastomeric adhesive/sealant that is also coated on the external edges of these components to provide a water-tight seal to better contain the coolant fluid in the form of water provided in the fuel cell stack.

Abstract: A fuel processing system is operable to remove substantially all of the sulfur present in an undiluted hydrocarbon fuel stock supply used to power a fuel cell power plant in a mobile environment, such as an automobile, bus, truck, boat, or the like, or in a stationary environment. The power plant hydrogen fuel source can be gasoline, diesel fuel, naphtha, light hydrocarbon fuels such as butane, propane, natural gas, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The undiluted hydrocarbon fuel supply is passed through a nickel desulfurizer bed wherein essentially all of the sulfur in the organic sulfur compounds react with the nickel reactant, and are converted to nickel sulfide while the desulfurized organic remnants continue through the remainder of the fuel processing system. The system does not require the addition of steam or a hydrogen source to the fuel stream prior to the desulfurizing step.

Abstract: An improved membrane electrode assembly for PEM fuel cells is provided. Catalyst layers (40, 44) are disposed, respectively, on both sides of the proton exchange membrane (48). Gas diffusion layers (38, 50) are disposed, respectively, on sides of the catalyst layers (40, 44) not in contact with the proton exchange membrane (48). Porous substrates (32, 34) are disposed, respectively, on sides of the gas diffusion layers (38, 50) not in contact with the catalyst layers (40, 44). The porous substrates (32, 34) are impregnated at their periphery with a thermoplastic material. Thermoplastic film layers (42, 46, 68) are employed at the periphery of the assembly (10) between component parts to bond and seal water transport plates (12' and 16) to each other, as well as substrates (32, 32', 34) to the membrane electrode assembly (20). A foam tape 60, 62, 62' are employed to seal water transport plates (12, 12', 16) to respective substrates (32, 32', 34).

Abstract: A fuel processing system is operable to remove substantially all of the sulfur present in an undiluted hydrocarbon fuel stock supply used to power a fuel cell power plant in a mobile environment, such as an automobile, bus, truck, boat, or the like, or in a stationary environment. The power plant hydrogen fuel source can be gasoline, diesel fuel, naphtha, light hydrocarbon fuels such as butane, propane, natural gas, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The undiluted hydrocarbon fuel supply is passed through a nickel desulfurizer bed wherein essentially all of the sulfur in the organic sulfur compounds react with the nickel reactant, and are converted to nickel sulfide while the desulfurized organic remnants continue through the remainder of the fuel processing system. The system does not require the addition of steam or a hydrogen source to the fuel stream prior to the desulfurizing step.

Abstract: A fuel processing system is operable to remove substantially all of the sulfur present in gasoline or diesel fuel used for operating an internal combustion engine. The fuel supply is passed through a nickel reactant desulfurizer bed wherein essentially all of the sulfur in organic sulfur compounds in the fuel combine with the nickel reactant in the desulfurizer bed, and are converted to nickel sulfide. The desulfurizing system can operate at ambient or elevated pressures. The fuel can be treated either in a liquid phase or in a vapor phase. The sulfur scrubbing operation can be performed either in a vehicle while the latter is being operated, or at the fueling station (gas station) prior to sale to the end user. The amount of sulfur in the fuel can be lowered to less than about 0.05 ppm. This extends the life of the catalytic converters in vehicles, reduces corrosion of parts of the internal combustion engine, and provides an environmentally compatible system.

Abstract: A self-inerting fuel cell system has a membrane/electrode assembly (MEA). A first fine pore plate is positioned at an anode side of the MEA and defines a fuel reactant flow field and a coolant flow field. A second fine pore plate is positioned at a cathode side of the MEA and defines an oxidant reactant flow field and a coolant flow field. A first means drives the fuel reactant flow field; a second means drives the oxidant flow field, and a third means drives the coolant flow field at a pressure less than that of the pressures of the reactant flow fields during on load operation of the fuel cell system. An air valve is coupled to an inlet or exit port of the oxidant flow field. A controller opens the air valve and activates the reactant and coolant flow fields during fuel cell operation, and closes the air valve and de-activates the reactant and coolant flow fields during fuel cell shut down which results in coolant flooding into the reactant flow fields to thereby inert the fuel cell system during shut down.

Abstract: A proton exchange membrane fuel cell has a noble metal or noble metal alloy catalyst 15 disposed in its air inlet manifold 13. During start up, a fuel cell is warmed to operating temperature by introducing a small amount of hydrogen into a flow of air to the air inlet 12 of the fuel cell where they react with the catalyst to produce heat at subflame temperatures. The adiabatic temperature rise of the gas stream is limited to about 150.degree. F. by limiting the hydrogen to about one volume percent of the fuel/oxidant mixture, thereby to be capable of raising the fuel cell temperature, for instance, from -40.degree. C. (-40.degree. F.) to about +45.degree. C. (+113.degree. F.), without flame, explosion or drying out of the membrane.

Abstract: A hydrogen-fueled fuel cell reacts residual fuel in the exhaust of the anode flow field either in a catalytic converter or by feeding the anode exhaust into the cathode oxidant stream. Control of flow of anode exhaust into the cathode oxidant stream may be in response to a flammability sensor, a gas composition analyzer, current output, or periodically in response to a timer; the anode exhaust may be fed either upstream or downstream of the cathode air inlet blower.

Abstract: A fuel gas reformer assembly for use in a fuel cell power plant includes fuel gas passages, some of which contain a particulate alumina packing in which a vaporized steam-hydrocarbon fuel stream mixture is heated. The walls of the fuel gas passages are provided with an alumina coating which protects the walls of the passages from corrosion. The alumina coating of the walls, and alumina packing are both overlain by an alkaline earth metal oxide layer, such as a calcium oxide layer, that acts to limit carbon build-up on the surfaces of the coated passage walls. Limiting of carbon build-up in the reformer passages prevents premature clogging of the passages. The carbon build-up-limiting layer is formed on components of the reformer passages by applying a water-based slurry of alkaline earth metal compounds to the reformer passage surfaces, and then drying the slurry so as to solidify it.

Abstract: The present invention relates to a method and apparatus for creating steam from the cooling stream of a proton exchange membrane (PEM) fuel cell. As the cooling stream exits the PEM fuel cell, a portion of the cooling fluid is extracted from the circulating cooling stream, thereby creating a secondary stream of cooling fluid. This secondary stream passes through a restriction, which decreases the pressure of the secondary stream to its saturation pressure, such that when the secondary stream enters a flash evaporator it transforms into steam. Creating steam from the cooling stream of a PEM fuel cell power plant provides the fuel processor with a co-generated source of steam without adding a significant amount of auxiliary equipment to the power plant.

Abstract: A fuel gas reformer assemblage for use in a fuel cell power plant is formed from a composite plate assembly which includes spaced-apart divider plates with interposed columns of individual fuel gas and burner gas passages. The fuel gas passages are provided with walls which are wash coated with a catalyzed alumina complex. The catalyst complex includes a nickel catalyst and a cerium and/or lanthanum oxide component which stabilizes the alumina against recrystalization in the catalyst complex. The catalyst complex also includes a calcium oxide component which inhibits carbon formation on the alumina surface. The cerium or lanthanum oxide and calcium oxide combine to provide a synergistic improvement in both alumina stabilization and also in inhibition of carbon deposits on the washcoated surfaces.

Abstract: A proton exchange membrane fuel cell has methanol or ethanol fed into the coolant passages during shut down so as to prevent water trapped therein from freezing in sub-freezing environments. Upon start-up, a controlled amount of air is fed through the cathode reactant flow field so that alcohol diffusing to the cathode catalyst is oxidized, producing heat which will raise the temperature of the fuel cell above freezing, and to a normal operating temperature. A heat exchanger in the coolant water circulating loop may be bypassed during start-up.

Abstract: A fuel atomizer for a liquid hydrocarbon fuel reformer/processor creates a high velocity atomized stream of a liquid fuel and steam, wherein the liquid fuel is quickly vaporized so as to limit carbon deposition from the fuel on the fuel vaporizer surfaces. The injector includes a small diameter fuel injection tube through which the liquid fuel and steam mixture is ejected at relatively high velocities. The liquid fuel forms an annular film which surrounds a steam core in the tube, which liquid droplet film and steam core composite are ejected from the tube into a stream of super heated steam, or steam and air. The stream of super heated steam substantially instantaneously vaporizes the fuel droplets from the film after the latter leaves the injection tube.

Abstract: An improved membrane electrode assembly for PEM fuel cells is provided. Catalyst layers (40, 44) are disposed, respectively, on both sides of the full planform proton exchange membrane (48). Gas diffusion layers (38, 50) are disposed, respectively, on sides of the catalyst layers (40, 44) not in communication with the full planform proton exchange membrane (48). Porous substrates (32, 34) are disposed, respectively, on sides of the gas diffusion layers (38, 50) not in communication with the catalyst layers (40, 44). The porous substrates (32, 34) are impregnated at their periphery with a sealant. The gas diffusion layers (38, 50) are coated with a sealant (60, 62) on respective sides thereof in regions which are in communication with sealant impregnated regions (36, 52) of the porous substrates (32, 34). The gas diffusion layers (38, 50), the porous substrates (32, 34), and the catalyst layers (40, 44) are co-extensive with the proton exchange membrane (48).

Abstract: The effluent gas stream from anaerobic waste water treatment digesters is treated to remove trace amounts of hydrogen sulfide and other contaminants. The chemical equation involved relies on the reaction of hydrogen sulfide with oxygen to form water plus elemental sulfur. The removal system includes a variable control line for adding air to the effluent gas stream; a filter for removing solids, entrained liquids and bacteria from the oxygen-enriched gas stream; a blower for directing the filtered gas stream into a potassium promoted activated carbon bed wherein the above chemical reaction takes place; and sensors for measuring the content of oxygen and hydrogen sulfide at the entrance and exit of the activated carbon bed. When the hydrogen sulfide content of the exiting gas stream exceeds a predetermined level, the amount of air added to the gas stream is increased until the predetermined level of hydrogen sulfide is achieved in the exiting gas stream.

Abstract: The effluent gas stream from anaerobic waste water treatment digesters is treated to remove trace amounts of hydrogen sulfide and other contaminants. The chemical equation involved relies on the reaction of hydrogen sulfide with oxygen to form water plus elemental sulfur. The removal system includes a variable control line for adding air to the effluent gas stream; a filter for removing solids, entrained liquids and bacteria from the oxygen-enriched gas stream; a blower for directing the filtered gas stream into a potassium promoted activated carbon bed wherein the above chemical reaction takes place; and sensors for measuring the content of oxygen and hydrogen sulfide at the entrance and exit of the activated carbon bed. When the hydrogen sulfide content of the exiting gas stream exceeds a predetermined level, the amount of air added to the gas stream is increased until the predetermined level of hydrogen sulfide is achieved in the exiting gas stream.

Abstract: A proton exchange membrane fuel cell device with an internal water management and transfer system includes a plurality of adjacently arranged proton exchange membrane assemblies including a proton exchange membrane component; a pair of porous anode and cathode catalyst layers situated on either side of the proton exchange membrane; and porous plate assemblies interposed between and in contact with each of the adjacent proton exchange membrane assemblies. Oxidant gas is supplied to oxidant gas supply channels, and fuel gas to fuel gas supply channels formed in the porous plate assemblies for distribution to the cathode and anode catalyst layers, respectively. A water coolant circulating system is formed in each of the porous plate assemblies and causes each of the porous plate assemblies to become saturated with coolant water. The reactant flow fields are pressurized to a pressure which exceeds the coolant water circulating pressure by a selected .DELTA.