Abstract: A fuel gas processing system is operable to remove substantially all of the sulfur present in a hydrocarbon fuel supply used to power a fuel cell power plant in a mobile vehicular environment. The power plant fuel can be gasoline, diesel fuel, kerosene, fuel oil, natural gas, or another fuel which contains relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The hydrocarbon fuel supply is passed through a nickel reactant 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 fuel continues through the remainder of the fuel processing system. The fuel cell power plant and the processing system can be used to power a mobile vehicle, such an automobile, truck, bus, or the like. An auxiliary supply of hydrogen is provided in order to power the fuel cell power plant during start up of the fuel processing system.

Abstract: A water treatment system for a fuel cell stack, wherein a degassifier provides for interaction between an oxidant and a coolant which has circulated throughout the fuel cell stack so that dissolved gases within the circulated coolant are removed.

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 water recovery fuel cell system includes a fuel cell defining a cathode flow field including a cathode input port and a cathode output port, and an anode flow field including an anode input port and an anode output port A humidity exchange device defines a supply gas input port, a supply gas output port, a process exhaust gas input port and a process exhaust gas output port. The supply gas input port is to be coupled to a source of oxidant gas, and the supply gas output port is coupled to the fuel cell power plant oxidant air supply including the cathode input port of the fuel cell. The process exhaust gas output port communicates at a junction with the cathode output port and a combustor exhaust derived from the anode flow field of the fuel cell, and the exhaust gas output port communicates with a power plant exhaust conduit. A power plant exhaust path is defined from the cathode output port to the power plant exhaust conduit via the humidity exchange device.

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: A water transport plate is provided with optimized physical characteristics to greatly improve fuel cell operation. In a preferred method of manufacturing, 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 laid-up. The lay-up is laminated with pressure and heat, carbonized, and graphitized to form a water transport plate for later machining as desired. The finished water transport plate exhibits optimal physical characteristics for bubble pressure, water permeability, median pore size, porosity, thru-plane resistivity and compressive yield strength.

Abstract: A fuel cell (10), having a proton exchange membrane (48), an anode and a cathode, and cathode and anode water transport plates (12, 16), includes a water capillary edge seal to optimize and greatly improve fuel cell operation without the need for additional seals or impregnation of the water transport plates. The water filled porous bodies of the water transport plates (12, 16) use the capillary forces of the water, which is a product of the electrochemical reaction of the fuel cell (10) and the preferred coolant, to prevent gas intrusion into the water system and over board leakage of the gases as well as the resultant hazardous mixture of gaseous fuel and oxidizing gas.

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 gas catalyst bed for use in a fuel cell power plant is formed from a monolithic open cell foam component, the open cell lattice of which forms gas passages through the catalyst bed. The monolithic component has a lattice of internal open cells which are both laterally and longitudinally interconnected so as to produce a diffuse gas flow pattern through the catalyst bed. All areas of the monolithic component which form the gas flow pattern are provided with an underlying high porosity wash coat layer. The porous surface of the wash coat layer is provided with a nickel catalyst layer, or a noble metal catalyst layer, such as platinum, rhodium, palladium, or the like, over which the gas stream being treated flows. The base foam lattice can be a metal such as aluminum, stainless steel, a steel-aluminum alloy, a nickel alloy, a ceramic, or the like material which can be wash coated.

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.