Abstract: A system and method for regenerating a device in an engine exhaust after-treatment system is provided. To regenerate the device, a syngas stream is introduced into the engine exhaust stream and combusts in the presence of a catalyst in the after-treatment system, raising the temperature. A supplemental liquid fuel stream is then selectively introduced into and is vaporized by the syngas stream to form a combined fuel stream. Combustion of the combined fuel stream with the engine exhaust in the presence of the catalyst further heats the device bringing it to a temperature suitable for regeneration. The catalyst can be upstream of or within the device being regenerated.

Abstract: A fuel cell system is provided that is capable of operating at high temperatures and near-ambient pressure with partial humidification of air supplied to the fuel cell stack. The fuel cells of the stack incorporate gas diffusion barrier layers at the cathode side thereof. The system includes a cooling loop for circulating a liquid coolant through the stack. In some embodiments, an incoming air stream is partially humidified with water vapor transferred from a cathode exhaust stream in a gas-exchange humidifier or enthalpy wheel. In other embodiments, a cathode recycle is employed to partially humidify the incoming air. The humidity of the air and cathode exhaust streams is maintained below a stack saturation point. Methods of operating the fuel cell system are also provided.

Abstract: A system and method for regenerating a device in an engine exhaust after-treatment system is provided. To regenerate the device, a syngas stream is introduced into the engine exhaust stream and combusts in the presence of a catalyst in the after-treatment system, raising the temperature. A supplemental liquid fuel stream is then selectively introduced into and is vaporized by the syngas stream to form a combined fuel stream. Combustion of the combined fuel stream with the engine exhaust in the presence of the catalyst further heats the device bringing it to a temperature suitable for regeneration. The catalyst can be upstream of or within the device being regenerated.

Abstract: A fuel cell system is provided that is capable of operating at high temperatures and near-ambient pressure with partial humidification of air supplied to the fuel cell stack. The fuel cells of the stack incorporate gas diffusion barrier layers at the cathode side thereof. The system includes a cooling loop for circulating a liquid coolant through the stack. In some embodiments, an incoming air stream is partially humidified with water vapor transferred from a cathode exhaust stream in a gas-exchange humidifier or enthalpy wheel. In other embodiments, a cathode recycle is employed to partially humidify the incoming air. The humidity of the air and cathode exhaust streams is maintained below a stack saturation point. Methods of operating the fuel cell system are also provided.

Abstract: Methods and apparatus for fuel release mitigation including enclosing a fuel cell stack (12) within an enclosure (20), supplying oxidant to the enclosure, circulating the oxidant within the enclosure to mix with any fuel present in the enclosure, withdrawing circulated oxidant from the enclosure; and supplying at least a portion of the circulated oxidant withdrawn from the enclosure to the stack as the cathode inlet stream.

Abstract: A fuel cell system is provided that is capable of operating at high temperatures and near-ambient pressure with partial humidification of air supplied to the fuel cell stack. The fuel cells of the stack incorporate gas diffusion barrier layers at the cathode side thereof. The system includes a cooling loop for circulating a liquid coolant through the stack. In some embodiments, an incoming air stream is partially humidified with water vapor transferred from a cathode exhaust stream in a gas-exchange humidifier or enthalpy wheel. In other embodiments, a cathode recycle is employed to partially humidify the incoming air. The humidity of the air and cathode exhaust streams is maintained below a stack saturation point. Methods of operating the fuel cell system are also provided.

Abstract: A compact, multitube steam reformer converts a fuel into a reformate stream comprising hydrogen. In one embodiment, the reformer comprises a closed vessel and a burner disposed within the vessel. The burner comprises a start fuel manifold for receiving and distributing a start fuel stream, an oxidant manifold for receiving and distributing an oxidant stream, and a burner fuel manifold for receiving and distributing a burner fuel stream. The oxidant manifold comprises a plurality of oxidant distribution tubes, each having an inlet end and an outlet end, disposed in a separator member. The burner fuel manifold comprises a plurality of burner fuel distribution tubes, each having an inlet end and an outlet end. The burner fuel distribution tubes extend through the start fuel manifold and the oxidant manifold and are fluidly isolated therefrom.

Abstract: A self-inerting fuel processing system is provided. In one embodiment, the present fuel processing system comprises a fuel processor comprising a reformer, at least one self-reducing catalyst bed, a recycle loop for circulating a gas stream through the fuel processor and the self-reducing catalyst bed(s) during shutdown of the fuel processing system, and an oxidant supply for introducing oxidant into the recycle loop during shutdown of the fuel processing system. A method for shutting down the fuel processing system is provided. A fuel cell electric power generation system incorporating the present fuel processing system is also provided.

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.

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.

Abstract: A self-inerting fuel processing system is provided. In one embodiment, the present fuel processing system comprises a fuel processor comprising a reformer, at least one self-reducing catalyst bed, a recycle loop for circulating a gas stream through the fuel processor and the self-reducing catalyst bed(s) during shutdown of the fuel processing system, and an oxidant supply for introducing oxidant into the recycle loop during shutdown of the fuel processing system. A method for shutting down the fuel processing system is provided. A fuel cell electric power generation system incorporating the present fuel processing system is also provided.

Abstract: A compact, multitube steam reformer converts a fuel into a reformate stream comprising hydrogen. In one embodiment, the reformer comprises a closed vessel and a burner disposed within the vessel. The burner comprises a start fuel manifold for receiving and distributing a start fuel stream, an oxidant manifold for receiving and distributing an oxidant stream, and a burner fuel manifold for receiving and distributing a burner fuel stream. The oxidant manifold comprises a plurality of oxidant distribution tubes, each having an inlet end and an outlet end, disposed in a separator member. The burner fuel manifold comprises a plurality of burner fuel distribution tubes, each having an inlet end and an outlet end. The burner fuel distribution tubes extend through the start fuel manifold and the oxidant manifold and are fluidly isolated therefrom.

Abstract: An autothermal reformer for converting a fuel into a reformate stream comprising hydrogen comprises (a) a closed vessel having a top end and a bottom end, the vessel comprising at least one insulation layer adjacent the interior surface of the vessel; (b) a first reactant manifold disposed within the vessel for receiving and distributing a first reactant stream, the first reactant manifold having a plurality of mixer tubes extending therefrom, each of the mixer tubes having an inlet end and an outlet end, the mixer tubes disposed in a separator member; and (c) a second reactant manifold disposed within the vessel for receiving and distributing a second reactant stream, the second reactant manifold comprising a plurality of injection tubes. Each of the injection tubes has an inlet end and an outlet end, extend through the first reactant manifold and are fluidly isolated therefrom.

Abstract: A fuel processing reactor is provided, comprising a shift catalyst bed disposed in a shell and tube reactor. The thermal stress on the present reactor during normal operation is reduced by cooling/heating both the shell and the tubes in the reactor. The present reactor may further comprise other beds such as hydrodesulfurizer catalyst beds, metal oxide beds, or sulfur polisher beds.

Abstract: A compact, multitube steam reformer converts a fuel into a reformate stream comprising hydrogen. In one embodiment, the reformer comprises a closed vessel and a burner disposed within the vessel. The burner comprises a start fuel manifold for receiving and distributing a start fuel stream, an oxidant manifold for receiving and distributing an oxidant stream, and a burner fuel manifold for receiving and distributing a burner fuel stream. The oxidant manifold comprises a plurality of oxidant distribution tubes, each having an inlet end and an outlet end, disposed in a separator member. The burner fuel manifold comprises a plurality of burner fuel distribution tubes, each having an inlet end and an outlet end. The burner fuel distribution tubes extend through the start fuel manifold and the oxidant manifold and are fluidly isolated therefrom.

Abstract: A fuel cell power plant, generally, has a fuel cell stack for electrochemically converting a hydrocarbon fuel into electricity. In order for the hydrocarbon fuel to be used by the fuel cell stack, it must be steam reformed into a hydrogen-rich process gas. This process gas has a carbon monoxide level that would be detrimental to the fuel cell stack, so the process gas is passed through a shift converter to decrease the carbon monoxide level therein prior to feeding the process gas to the fuel cell stack. In order to decrease the level of carbon monoxide without the need to increase the size of the shift converter catalyst bed, or lower the temperature of the process gas as it enters the shift converter to an undesirably low temperature, the shift converter design that utilizes an upstream adiabatic zone and a downstream actively cooled zone. The actively cooled zone is cooled by a pressurized water coolant which boils as it cools the process gas stream.

Abstract: A compact and efficient fuel reformer which is operable to produce a hydrogen-enriched process fuel from a raw fuel such as natural gas, or the like includes a compact array of catalyst tubes which are contained in a heat-insulated housing. The catalyst tube array preferably includes a multitude of catalyst tubes that are arranged in a hexagonal array. The housing includes internal hexagonal thermal insulation so as to ensure even heating of the catalyst tubes. The diameter of the tubes is sized so that spacing between adjacent tubes in the array can be minimized for efficient heat transfer. The interior of each of the catalyst tubes includes a hollow dead-ended central tube which serves as a fines trap for collecting catalyst fines that may become entrained in the fuel stream. The catalyst tubes are also provided with an upper frusto-conical portion which serves to extend the catalyst bed and provide a catalyst reserve.

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 control system and method for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein the fuel processing system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of the fuel processing elements having an individual output and the plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic gas load demand. The control system includes a device for receiving communication from the downstream process indicative of the dynamic load demand and a device for controlling the collective output level of the gas in response to the dynamic load demand.

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.