Abstract: Improved feedstocks for hydrogen-producing fuel processing and fuel cell systems, and fuel processing and fuel cell systems incorporating the same. The fuel processing systems include a fuel processor adapted to produce a product hydrogen stream from at least one feed stream containing at least a carbon-containing feedstock and an aversive agent. The fuel processing systems may also include a fuel cell stack adapted to produce an electric current from the product hydrogen stream. The feedstock is at least substantially formed of a hydrocarbon or alcohol. In some instances the feedstock includes methanol and the aversive agent is delivered to a hydrogen-producing region of the fuel processor with the carbon containing feedstock. The aversive agent can include at least one odorant, flavorants regurgitant, and/or dye. In other instances, the feed stream includes water or the feed stream is delivered to a fuel stack that produces and electric current therefrom.

Abstract: Combustion-based heating assemblies and hydrogen-producing fuel processing assemblies that include at least a reforming region adapted to be heated by the heating assemblies. The heating assembly may include at least one fuel chamber and at least one heating and ignition source. The at least one fuel chamber may be adapted to receive at least one fuel stream at a first temperature. The fuel stream may include a liquid, combustible, carbon-containing fuel having an ignition temperature greater than the first temperature at which the fuel stream is delivered to the fuel chamber. The at least one heating and ignition source may be adapted to heat at least a portion of the fuel chamber to raise the temperature of at least a portion of the carbon-containing fuel to a second temperature at least as great as the ignition temperature and to ignite the carbon-containing fuel. Methods of use are also disclosed.

Abstract: Liquid leak detection systems, and fuel cell systems and hydrogen-producing fuel processing systems containing the same. The liquid leak detection systems are adapted to detect liquid leaks from the fuel cell and/or fuel processing systems and to respond thereto, such as by interrupting the delivery of liquid reactants, by generating an alert, by transitioning the fuel processing system to a different operating state, and/or by shutting down the fuel processing and/or fuel cell system. The liquid leak detection systems may include a controller and at least one liquid detector, and in some embodiments may include a cover. In some embodiments, the liquid detector includes a signal emitter and a signal detector. In some embodiments, the liquid detector includes at least a pair of spaced-apart conductive members that nominally define an open circuit. In some embodiments, the cover is adapted to repel water and/or includes conductive particulate.

Abstract: Feedstock delivery systems and hydrogen-producing fuel processing assemblies and fuel cell systems containing the same. The feedstock delivery systems include a liquid pump that draws at least one liquid feedstock from a supply and delivers at least one feed stream containing the feedstock(s) to a fuel processor, such as to the hydrogen-producing region thereof. The feedstock delivery system further includes a recycle conduit that establishes a fluid flow path for the liquid feedstock(s) from a location downstream of the pump back to a location upstream of the pump. In some embodiments, the feedstock delivery system further includes a flow restrictor associated with the recycle conduit and a pressure-actuated valve that selectively permits the recycled feedstock to bypass the flow restrictor. In some embodiments, the pump is configured to draw a greater flow rate of the feed stream from the supply than is delivered to the fuel processor.

Abstract: Systems and methods for producing hydrogen gas with a fuel processing system that includes a hydrogen-producing region that produces hydrogen gas from a feed stream and a heating assembly that consumes a fuel stream to produce a heated exhaust stream for heating the hydrogen-producing region. In some embodiments, the heating assembly heats the hydrogen-producing region to at least a minimum hydrogen-producing temperature. In some embodiments, the rate at which an air stream is delivered to the heating assembly is controlled to selectively increase or decrease the temperature of the heated exhaust stream. In some embodiments, the feed stream and the fuel stream both contain a carbon-containing feedstock and at least 25 wt % water. In some embodiments, the feed and fuel streams have the same composition.

Abstract: Hydrogen-producing fuel processing systems, hydrogen purification membranes, hydrogen purification devices, and fuel processing and fuel cell systems that include hydrogen purification devices. In some embodiments, the fuel processing systems and the hydrogen purification membranes include a metal membrane, which is at least substantially comprised of palladium or a palladium alloy. In some embodiments, the membrane contains trace amounts of carbon, silicon, and/or oxygen. In some embodiments, the membranes form part of a hydrogen purification device that includes an enclosure containing a separation assembly, which is adapted to receive a mixed gas stream containing hydrogen gas and to produce a stream that contains pure or at least substantially pure hydrogen gas therefrom. In some embodiments, the membrane(s) and/or purification device forms a portion of a fuel processor, and in some embodiments, the membrane(s) and/or purification device forms a portion of a fuel processing or fuel cell system.

Abstract: Hydrogen-producing fuel processing systems, hydrogen purification membranes, hydrogen purification devices, fuel processing and fuel cell systems that include hydrogen purification devices, and methods for operating the same. In some embodiments, operation of the fuel processing system is initiated by heating at least the reforming region of the fuel processing system to at least a selected hydrogen-producing operating temperature. In some embodiments, an electric heater is utilized to perform this initial heating. In some embodiments, use of the electric heater is discontinued after startup, and a burner or other combustion-based heating assembly combusts a fuel to heat at least the hydrogen producing region, such as due to the reforming region utilizing an endothermic catalytic reaction to produce hydrogen gas.

Abstract: Pressure swing adsorption (PSA) assemblies and hydrogen-producing fuel processing assemblies and/or fuel cell systems including the same. The PSA assemblies include, or are utilized with, combustion fuel stream supply systems that are adapted to regulate the flow of a byproduct stream from the PSA assembly for delivery to a heating assembly for use as a combustible fuel stream, such as to maintain at least a hydrogen-producing region of the fuel processing system at a hydrogen-producing temperature or range of temperatures. In some embodiments, the combustion fuel stream supply system is configured to ensure that the supply of combustible fuel from the PSA assembly to the heating assembly contains at least a sufficient fuel value, such as to maintain at least the hydrogen-producing region at or within a predetermined hydrogen-producing temperature or range of temperatures.

Abstract: Hydrogen-producing fuel processing assemblies and methods for delivering feedstock to a hydrogen-producing region of a hydrogen-producing fuel processing assembly. In some embodiments, the fuel processing assemblies include a feedstock delivery system that includes a pump assembly and a stall prevention mechanism that is adapted to reduce pressure in an outlet conduit during periods in which the pump assembly is not emitting a liquid outlet stream within or above a hydrogen-producing pressure range. In some embodiments, pressure in the outlet conduit is isolated from pressure in the hydrogen-producing region of the fuel processing assembly and is reduced during periods in which a liquid stream is not being pumped within or above a hydrogen-producing pressure range.

Abstract: Systems and methods for recovering thermal energy from a fuel processing system comprising a fuel processor and a fuel cell stack in communication with a household that is adapted to apply at least electrical loads, and optionally electrical and thermal loads, to the fuel processing system. The systems further include a thermal energy recovery system that is adapted to recover thermal energy from the fuel processing system and which includes a plurality of thermal energy reservoirs. The recovery system includes a delivery system that is adapted to selectively deliver heat exchange fluid from at least one of the plurality of thermal energy reservoirs into thermal communication with the fuel processing system to recover thermal energy therefrom. In some embodiments, at least one of the thermal energy reservoirs forms at least a portion of a potable hot water supply for the household.

Abstract: Feedstock delivery systems for hydrogen generation assemblies having a hydrogen-producing region and a heating assembly. The delivery system provides a hydrogen-production fluid to the hydrogen-producing region and provides a heating fuel to the heating assembly. The delivery system includes a pressure vessel having an interior cavity containing the heating fuel and the hydrogen-production fluid, which are disposed in the pressure vessel in a pressurizing—pressurized relationship, in which the heating fuel is discharged from the pressure vessel under it own pressure and the hydrogen-production fluid is discharged under pressure applied by the heating fuel. The feedstock delivery system may separately discharge the hydrogen-production fluid and the heating fuel and may include a pressure transmitter disposed between the hydrogen-production fluid and the heating fuel.

Abstract: Pressure swing adsorption (PSA) assemblies with purge control systems, and hydrogen-generation assemblies and/or fuel cell systems containing the same. The PSA assemblies are operated according to a PSA cycle to produce a product hydrogen stream and a byproduct stream from a mixed gas stream. The byproduct stream may be delivered as a fuel stream to a heating assembly, which may heat the hydrogen-producing region that produces the mixed gas stream. The PSA assemblies may be adapted to regulate the flow of purge gas utilized therein, such as according to a predetermined, non-constant profile. In some embodiments, the flow of purge gas is regulated to maintain the flow rate and/or fuel value of the byproduct stream at or within a determined range of a threshold value, and/or to regulate the flow of purge gas to limit the concentration of carbon monoxide in a heated exhaust stream produced from the byproduct stream.

Abstract: Systems and methods for producing hydrogen gas with a fuel processing system that includes a hydrogen-producing region that produces hydrogen gas from a feed stream and a heating assembly that consumes a fuel stream to produce a heated exhaust stream for heating the hydrogen-producing region. In some embodiments, the heating assembly heats the hydrogen-producing region to at least a minimum hydrogen-producing temperature. In some embodiments, the feed stream and the fuel stream both contain a carbon-containing feedstock and at least 25 wt % water. In some embodiments, at least one of the feed and fuel streams contain at least one additional component. In some embodiments, the feed and fuel streams have the same composition. In some embodiments, the feed and fuel streams are drawn or obtained from a common source or supply, and in some embodiments as a liquid stream that is selectively apportioned to form the feed and fuel streams.

Abstract: Fuel processing and fuel cell systems with feedstock delivery systems that are designed to deliver a mixed component feed stream to a hydrogen-producing region for the production of hydrogen gas therefrom and to selectively deliver the feed stream to a heating assembly for use as a combustible fuel stream for heating at least the hydrogen-producing region. The feed stream contains water and a carbon-containing feedstock, and may contain at least 31 vol % water. In some embodiments, the feedstock delivery system may be adapted to mix the components of the feed stream at a determined mix ratio and to deliver this feed stream to the fuel processor(s). The fuel processing system may also include one or more fuel cell stacks that are adapted to produce an electric current from the product hydrogen stream produced by the fuel processing system.

Abstract: Feedstock delivery systems and hydrogen-producing fuel processing assemblies and fuel cell systems containing the same. The feedstock delivery systems include a liquid pump that draws at least one liquid feedstock from a supply and delivers at least one feed stream containing the feedstock(s) to a fuel processor, such as to the hydrogen-producing region thereof. The feedstock delivery system further includes a recycle conduit that establishes a fluid flow path for the liquid feedstock(s) from a location downstream of the pump back to a location upstream of the pump. In some embodiments, the feedstock delivery system further includes a flow restrictor associated with the recycle conduit and a pressure-actuated valve that selectively permits the recycled feedstock to bypass the flow restrictor. In some embodiments, the pump is configured to draw a greater flow rate of the feed stream from the supply than is delivered to the fuel processor.

Abstract: Hydrogen-producing fuel processing systems, hydrogen purification membranes, hydrogen purification devices, and fuel processing and fuel cell systems that include hydrogen purification devices. In some embodiments, the fuel processing systems and the hydrogen purification membranes include at least one metal membrane, which is at least substantially comprised of a palladium alloy. In some embodiments, the membrane is formed from an alloy of palladium and gold and which contains trace amounts of carbon, silicon, and/or oxygen. In some embodiments, the membranes form part of a hydrogen purification device that includes an enclosure containing a separation assembly, which is adapted to receive a mixed gas stream containing hydrogen gas and to produce a stream that contains pure or at least substantially pure hydrogen gas therefrom.

Abstract: Hydrogen-producing fuel processing systems, hydrogen purification membranes, hydrogen purification devices, and fuel processing and fuel cell systems that include hydrogen purification devices. In some embodiments, the fuel processing systems and the hydrogen purification membranes include a metal membrane, which is at least substantially comprised of palladium or a palladium alloy. In some embodiments, the membrane contains trace amounts of carbon, silicon, and/or oxygen. In some embodiments, the membranes form part of a hydrogen purification device that includes an enclosure containing a separation assembly, which is adapted to receive a mixed gas stream containing hydrogen gas and to produce a stream that contains pure or at least substantially pure hydrogen gas therefrom. In some embodiments, the membrane(s) and/or purification device forms a portion of a fuel processor, and in some embodiments, the membrane(s) and/or purification device forms a portion of a fuel processing or fuel cell system.

Abstract: Pressure swing adsorption (PSA) assemblies with purge control systems, and hydrogen-generation assemblies and/or fuel cell systems containing the same. The PSA assemblies are operated according to a PSA cycle to produce a product hydrogen stream and a byproduct stream from a mixed gas stream. The byproduct stream may be delivered as a fuel stream to a heating assembly, which may heat the hydrogen-producing region that produces the mixed gas stream. The PSA assemblies may be adapted to regulate the flow of purge gas utilized therein, such as according to a predetermined, non-constant profile. In some embodiments, the flow- of purge gas is regulated to maintain the flow rate and/or fuel value of the byproduct stream at or within a determined range of a threshold value, and/or to regulate the flow of purge gas to limit the concentration of carbon monoxide in a heated exhaust stream produced from the byproduct stream.

Abstract: Pressure swing adsorption (PSA) assemblies with temperature-based breakthrough detection systems, as well as to hydrogen-generation assemblies and/or fuel cell systems containing the same, and to methods of operating the same. The detection systems are adapted to detect a measured temperature associated with adsorbent in an adsorbent bed of a PSA assembly and to control the operation of at least the PSA assembly responsive at least in part thereto, such as responsive to the relationship between the measured temperature and at least one reference temperature. The reference temperature may include a stored value, a previously measured temperature and/or a temperature measured elsewhere in the PSA assembly. In some embodiments, the reference temperature is associated with adsorbent downstream from the adsorbent from which the measured temperature is detected.

Abstract: Pressure swing adsorption (PSA) assemblies with temperature-based breakthrough detection systems, as well as to hydrogen-generation assemblies and/or fuel cell systems containing the same, and to methods of operating the same. The detection systems are adapted to detect a measured temperature associated with adsorbent in an adsorbent bed of a PSA assembly and to control the operation of at least the PSA assembly responsive at least in part thereto, such as responsive to the relationship between the measured temperature and at least one reference temperature. The reference temperature may include a stored value, a previously measured temperature and/or a temperature measured elsewhere in the PSA assembly. In some embodiments, the reference temperature is associated with adsorbent downstream from the adsorbent from which the measured temperature is detected.