Abstract: A fuel cell system includes a fuel cell for reacting a hydrogen rich gas; a fuel processor system for converting a hydrocarbon fuel-steam mixture into said hydrogen rich gas; and a system for preparing the hydrocarbon fuel-steam mixture which includes (a) structure for superheating a hydrocarbon fuel so as to provide a superheated fuel, and (b) structure for mixing water with the superheated fuel so as to provide the hydrocarbon fuel-steam mixture.

Abstract: A fuel processing method is operable to remove substantially all of the sulfur present in an undiluted hydrocarbon fuel stock supply which is 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, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, thiophenes and the like. The undiluted hydrocarbon fuel supply is passed through a nickel reactant desulfurizer bed wherein essentially all of the sulfur in the organic sulfur compounds reacts with the nickel reactant, and is converted to nickel sulfide, while the now desulfurized hydrocarbon fuel supply continues through the remainder of the fuel processing system. The method involves adding hydrogen to the fuel stream prior to the desulfurizing step. The method can be used to desulfurize either a liquid or a gaseous fuel stream.

Abstract: An improved water management system for PEM fuel cells is provided. Catalyst layers are disposed on both sides of a proton exchange membrane. Porous plates are positioned adjacent the catalyst layers. Water transport plates are positioned adjacent the porous plates and the reactant gas are humidified at their inlets, in one embodiment by fins, while moisture is removed in the fuel flow path and at the oxidant outlet, in one embodiment by other fins.

Abstract: A cell stack assembly includes a plurality of plates defining a primary cell stack portion having a primary air flow path, a fuel flow path and a primary coolant flow path; and an auxiliary coolant stack portion defining an auxiliary air flow path and an auxiliary coolant flow path, the auxiliary air flow path being communicated with the primary air flow path, whereby water is condensed from air in the auxiliary air flow path.

Abstract: Recovery of PEM fuel cell performance is achieved by evacuating (61, 62) or by flowing water absorbing gas (46) through, or both, the fuel flow field (12, 13, 19, 20), the air flow field (25, 26, 30, 31), and the water flow field (36, 39), while resistance of the individual cells, or of the fuel cell stack, is measured; the dry out process is continued until the resistance of the cells (or the resistance per cell, measured across the fuel cell stack as a whole), has increased by at least 5 to 1 (preferably 10 to 1) over the normal resistance of the cells. The water absorbing gas may be air (23) or nitrogen (47); it may be at ambient temperature or heated (50).

Abstract: In a near ambient pressure operated auto-thermal reformer fuel gas system, a precooler between the auto-thermal reformer and shift converter. The precooler includes a spraying water inlet, an inlet for the reformed gas and a packing of high surface area material which increases the available surface area for water evaporation in the precooler so as to effectively cool the hot reformed gas.

Abstract: The invention reduces free water volume in a fuel cell power plant so support systems of the plant are freeze tolerant. The fuel cell power plant includes a coolant system having a sealed cooler plate that circulates an antifreeze coolant in heat exchange with a fuel cell and that collects fuel cell water; a water vapor removal system that removes water vapor from the antifreeze coolant to regulate the antifreeze concentration; and a start-up system having a start-up heat exchanger and a start-up valve that selectively direct heated antifreeze coolant into the cooler plate for a start-up procedure. The plant may also include a fuel processing system that utilizes the removed water vapor, and that is in heat exchange with the start-up heat exchanger. The antifreeze coolant is a low vapor pressure solution, such as an alkanetriol or polyethylene glycol.

Abstract: A fuel cell stack assembly includes a fuel cell component and at least one manifold positioned adjacent to the fuel cell component; and a cable disposed around the fuel cell stack assembly for securing the manifold to the fuel cell component, the cable having an adjustable securing member for adjusting tightness of the cable around the fuel cell assembly.

Abstract: A method and apparatus for increasing the operational efficiency of a fuel cell power plant including a cell stack assembly having a plurality of fuel cells in electrical communication with one another, each of the fuel cells including an anode substrate in fluid communication with an anode flow field plate. The proposed method includes forming a fuel channel in the anode flow field plate, providing a fuel stream to a fuel channel and interrupting the fuel channel at a location along the fuel channel so that the fuel stream is directed to permeate the anode substrate before being exhausted from the fuel cells.

Abstract: A vehicle (150) includes a fuel cell stack (151) started when the stack is below freezing, by connection (158) to the vehicle propulsion system (159) within a few seconds of starting the flow of fuel (179) and oxidant (173), or when open circuit voltage (155, 156) is detected. The fuel is in excess of stochiometry requirement and the oxidant is in excess of at least twice stochiometric requirement, either may be at about atmospheric pressure or at 4 kPa (0.6 psi) or more above the pressure of any water in said water passages, and either may be below freezing. Water transport plates (84, 86, 88, 89) have water passages connected to a water circulation loop (170) including a reservoir (164) having an auxiliary heater (161) connected (160) to the stack. Warming of cell stack materials and ice in the water transport plates, heat of fusion of melting ice, warming of melted water, and evaporative cooling of water melted in the water transport plates keep the fuel cell cool until liquid coolant can be circulated.

Abstract: A steam reformer for converting a reactor fuel into a product gas includes a catalyst bed which is formed from catalyst blocks which are configured so as to match the configuration of the catalyst bed chamber. The steam reformer side walls have a thermal coefficient of expansion which is greater than the thermal coefficient of expansion of the catalyst. By forming specifically configured catalyst bed blocks, slumping and subsequent damage of the catalyst blocks is eliminated.

Abstract: A fuel cell (40) has a proton exchange membrane (41) having a rectangular central portion (42) and flaps (43-46) extending from the central portion. The flaps are wrapped around the cathode and anode substrates (14, 26) to provide respective edge seals therefor. A liquified adhesive adheres the flaps to the substrates and intervening filler material (33) so as to form a unitized electrode assembly.

Abstract: A sealant system 13 for a manifold 10 of a proton exchange membrane fuel cell includes low temperature cured or heat cured silicone rubber bridges 14, 14a, 14c between the end plates 9 to compensate for the uneven edges of various fuel cell component layers, and a layer 15 of silicone rubber foam or sponge, or a molded silicone rubber gasket 15a, extending across the bridges and along the end plates, around the entire contact perimeter surfaces of the manifold, to seal the manifold to the fuel cell. The cured silicone rubber may extend along the end plates between the bridges. A rubber strip 20 may be adhered to the silicone rubber bridges and end plates. The bridges may comprise a first layer 22 of low shrinkage self-leveling RTV liquid rubber with viscosity in the range of 10,000-20,000 cps and a second layer 14 of RTV liquid rubber.

Abstract: A system and method are provided for managing water coolant in a PEM fuel cell system's (10) coolant circuit (14). Gas-liquid separating apparatus (26) serves to efficiently transport liquid coolant containing gases, and to separate gases from the liquid coolant. The liquid coolant having the gases removed therefrom is then circulated through the liquid circuit by means of a conventional pump (24). A vacuum pump (28), such as a liquid eductor (28′), associated with the gas-liquid separating apparatus (26), serves to efficiently transport gas-phase and/or gas-liquid phase, fluids and to assist in the degasification of the liquid coolant. The eductor discharges to a separator/accumulator (30; 30′) which further facilitates separation of gases from liquid coolant.

Abstract: A procedure for purging a fuel cell system at start-up or shutdown comprises directing the organic fuel, along with air, into a burner to produce a gas that is essentially inert to the fuel cell, such as a gas of nitrogen, carbon dioxide and water vapor. That inert gas is passed through either or both the fuel cell and fuel processing system components, such as a reformer and shift converter, to purge those components of undesirable gases. In the case of shutdown, after the cell has been disconnected from the primary load, the inert gas produced in the burner is passed either in series or in parallel through the fuel cell and fuel processing system.

Abstract: A fuel cell system is shut down by disconnecting the primary load, shutting off the air flow, and controlling the fuel flow into the system (including shutting off the fuel flow) and the gas flow out of the system in a manner that results in the fuel cell gases coming to equilibrium across the cells at a gas composition of at least 0.0001% hydrogen (by volume), and preferably between 1.0% and less than 4.0% hydrogen, by volume, with a balance of nitrogen and possibly other gases inert and harmless to the fuel cell, all the oxygen having been consumed by reacting with the hydrogen within the cell. That gas composition is maintained within the cells throughout shut-down, such as by adding hydrogen to replace any that is consumed by reaction with air leaking into the cells during the period of shut-down. This shut-down procedure causes virtually no cell performance losses.

Abstract: A fuel cell power plant includes a first cell stack assembly having a plurality of planar fuel cells in electrical communication with one another and a second cell stack assembly having a plurality of planar fuel cells in electrical communication with one another. An inter-stack manifold assembly is disposed between the first and second cell stack assemblies and provides an electrical pathway between the first and second cell stack assemblies. A baffle is formed internally to the manifold assembly for feeding a substantially uniform proportion of a reactant stream to the first and second cell stack assemblies while collecting an exhausted reactant stream from the first and second cell stack assemblies.

Abstract: A fuel gas-steam reformer assembly, preferably an autothermal reformer assembly, for use in a fuel cell power plant, includes a mixing station for intermixing a relatively high molecular weight fuel and an air-steam stream so as to form a homogeneous fuel-air-steam mixture for admission into a catalyst bed. The catalyst bed can include catalyzed alumina pellets, or a monolith such as a foam or honeycomb body which is preferably formed from a high temperature material such as a steel alloy, or from a ceramic material. The air-steam stream is fed into a manifold in the mixing station. The mixing station also comprises a plurality of tubes which open into the catalyst bed, and which pass through the manifold. The tubes extend through the manifold and include tangential openings which interconnect the interior of the tubes with the manifold. The openings have axes which are tangential to the circumference of each of the tubes.

Abstract: The invention is a bi-zone water transport plate for a fuel cell wherein the plate includes a water permeability zone and a bubble barrier zone. The bubble barrier zone extends between all reactive perimeters of the plate, has a pore size of less than 20 microns, and has a thickness of less than 25 percent of a shortest distance between opposed contact surfaces of the plate. The water permeability zone has a pore size of at least 100 percent greater than the pore size of the bubble barrier zone, and has a thickness of greater than 75 percent of the shortest distance between the opposed contact surfaces of the plate. By having a separate bubble barrier zone, the plate affords enhanced water permeability while the bubble barrier maintains a gas seal.

Abstract: A fuel processing system is operative to remove substantially all of the sulfur present in a logistic fuel stock supply. The fuel stock can be gasoline, diesel fuel, or other like fuels which contain relatively high levels of organic sulfur compounds such as mercaptans, sulfides, disulfides, and the like. The system is a part of a fuel cell power plant. The fuel stock supply is fed through a reformer where the fuel is converted to a hydrogen rich fuel which contains hydrogen sulfide. The hydrogen sulfide-containg reformer exhaust is passed through a sulfur scrubber, to which is added a small quantity of air, which scrubber removes substantially all of the sulfur in the exhaust stream by means of the Claus reaction. The desulfurizing step causes sulfur to deposit on the scrubber bed, which after a period of time, will prevent further sulfur from being removed from the reformer exhaust stream.