Abstract: A power system (110; 210; 310) combines a power source (14) having a DC output (20A, 20B) with an AC supply from the AC grid (12) to provide AC to customer's loads (16) and DC to various DC auxiliary loads (134, 134A). The DC output of the DC power source (14) is connected in steady-state to the DC input (120A, 120B, 60) of a converter/bi-directional inverter (122; 222) for conversion therein to AC for connection (124, 124A, 32) to the customer's loads (16) and (124, 124B) to any AC auxiliary loads (134, 234). During start-up of the DC power source (14), an open isolation switch (70) disconnects that DC power source (14) from the bi-directional inverter (122; 222). A start-up power supply (50, 60; 250, 60; 90, 180, 60) selectively connects (56; 94) between the AC power grid (12) and the bi-directional inverter (122; 222) and/or DC controllers (134A) to provide a supply of rectified DC power at the inverter DC input and to certain DC auxiliary loads (134, 234).

Abstract: An H2-permeable membrane system (117) comprises an electroless-deposited plating (115) of Pd or Pd alloy on a porous support (110, 110?). The Pd plating comprises face-centered cubic crystals cumulatively having a morphology of hexagonal platelets. The permeability to H2 of the membrane plating (115) on the porous support is significantly enhanced, being at least greater than about 1.3×10?8 mol·m?1·s?·Pa?0.5 at 350° C., and even greater than about 3.4×10?8 mol·m?1·s?1·Pa?0.5. The porous support (110, 110?) may be stainless steel (1100 and include a thin ceramic interlayer (110?) on which the Pd is plated. The method of providing the electroless-deposited plating includes preheating a Pd electroless plating solution to near a plating temperature substantially greater than room temperature, e.g. 60° C., prior to plating.

Abstract: A durable catalyst support/catalyst is capable of extended water gas shift operation under conditions of high temperature, pressure, and sulfur levels. The support is a homogeneous, nanocrystalline, mixed metal oxide of at least three metals, the first being cerium, the second being Zr, and/or Hf, and the third importantly being Ti, the three metals comprising at least 80% of the metal constituents of the mixed metal oxide and the Ti being present in a range of 5% to 45% by metals-only atomic percent of the mixed metal oxide. The mixed metal oxide has an average crystallite size less than 6 nm and forms a skeletal structure with pores whose diameters are in the range of 4-9 nm and normally greater than the average crystallite size. The surface area of the skeletal structure per volume of the material of the structure is greater than about 240 m2/cm3. The method of making and use are also described.

Abstract: A durable Pd-based alloy is used for a H2-selective membrane in a hydrogen generator, as in the fuel processor of a fuel cell plant. The Pd-based alloy includes Cu as a binary element, and further includes “X”, where “X” comprises at least one metal from group “M” that is BCC and acts to stabilize the ? BCC phase for stability during operating temperatures. The metal from group “M” is selected from the group consisting of Fe, Cr, Nb, Ta, V, Mo, and W, with Nb and Ta being most preferred. “X” may further comprise at least one metal from a group “N” that is non-BCC, preferably FCC, that enhances other properties of the membrane, such as ductility. The metal from group “N” is selected from the group consisting of Ag, Au, Re, Ru, Rh, Y, Ce, Ni, Ir, Pt, Co, La and In. The at. % of Pd in the binary Pd—Cu alloy ranges from about 35 at. % to about 55 at. %, and the at. % of “X” in the higher order alloy, based on said binary alloy, is in the range of about 1 at. % to about 15 at. %.

Abstract: A homogeneous ceria-based mixed-metal oxide, useful as a catalyst support, a co-catalyst and/or a getter has a relatively large surface area per weight, typically exceeding 150 m2/g, a structure of nanocrystallites having diameters of less than 4 nm, and including pores larger than the nanocrystallites and having diameters in the range of 4 to about 9 nm. The ratio of pore volumes, VP, to skeletal structure volumes, VS, is typically less than about 2.5, and the surface area per unit volume of the oxide material is greater than 320 m2/cm3, for low internal mass transfer resistance and large effective surface area for reaction activity. The mixed metal oxide is ceria-based, includes Zr and or Hf, and is made by a novel co-precipitation process. A highly dispersed catalyst metal, typically a noble metal such as Pt, may be loaded on to the mixed metal oxide support from a catalyst metal-containing solution following a selected acid surface treatment of the oxide support.

Abstract: A homogeneous ceria-based mixed-metal oxide, useful as a catalyst support, a co-catalyst and/or a getter has a relatively large surface area per weight, typically exceeding 150 m2/g, a structure of nanocrystallites having diameters of less than 4 nm, and including pores larger than the nanocrystallites and having diameters in the range of 4 to about 9 nm. The ratio of pore volumes, VP, to skeletal structure volumes, VS, is typically less than about 2.5, and the surface area per unit volume of the oxide material is greater than 320 m2/cm3, for low internal mass transfer resistance and large effective surface area for reaction activity. The mixed metal oxide is ceria-based, includes Zr and or Hf, and is made by a novel co-precipitation process. A highly dispersed catalyst metal, typically a noble metal such as Pt, may be loaded on to the mixed metal oxide support from a catalyst metal-containing solution following a selected acid surface treatment of the oxide support.

Abstract: An arrangement is provided in a fuel cell power plant (10) for dispensing (58 74, 60, 64) a liquid medium, such as water (66), into a process oxidant (air) stream (53) that flows through one gas channel (42) in an energy recovery device (ERD) (32). An exhaust gas stream (48) containing heat and moisture from the fuel cell (12) flows through another channel (44) in the ERD. An enthalpy exchange barrier (46) separates the one and the other gas channels, but allows mass and/or heat transfer therebetween. The water is injected into the air stream (53) in a controlled (70, 74) amount, and perhaps temperature (78), in response to sensed parameters (80, 84, 90) of the power plant, including the process air stream, to adjust one or more conditions in the power plant. Controlling ERD dryness, providing a defrost capability for the ERD, and/or preventing excessive water accumulation in the system are several of the conditions controlled.

Abstract: A first AC power source comprising a power plant (18), and a second power source, typically grid (10), are normally connected via a high speed isolation switching means (19) to provide sufficient AC power to a critical load (14). The power plant (18) comprises a power generating means, e.g. a fuel cell, (60) and a power conditioning system (PCS) (62) having an inverter (64). Power assurance means (65; 10?, 66, 64, 70; 74, 75) is/are operatively connected to at least one of the first and second power sources to enhance an even and continuous supply of power to the critical load (14). The power assurance means (65; 10?, 66, 64, 70; 74, 75) is/are operatively connected to the PCS inverter (64), and may be one, or a combination of, a surge suppression means (65), a double-conversion power connection means (10?, 66, 64, 70) having a rectifier (66); and/or stored energy means (74), such as a capacitor (75).

Abstract: An arrangement and process are provided for regulating the humidification or dew point of inlet air supplied (124, 224, 324, 424) to combustion-supported reaction means (20, 120) of a fuel processing system in a fuel cell power plant (110, 210, 310, 410). In addition to flowing exhaust gas(es) (28, 128) in heat and energy exchange relation with inlet air through a primary energy recovery device (ERD) (30) of the gas/gas type, a supplemental ERD (50) of the gas/liquid (water) type uses water temperature to passively condense moisture from a gas stream, either of inlet air or of exhaust gas, to regulate the dew point of the air supplied to the combustion-supported reaction means (20, 120). The supplemental ERD (50) may have a gas channel (134) and a water channel (132) separated by an enthalpy exchange barrier (136), and may be relatively upstream or downstream of the primary ERD (30) relative to the flow of inlet air through the latter to regulate dew point indirectly or directly, respectively.

Abstract: Method and apparatus are provided for removing contaminants from a hydrogen processor feed stream, as in a fuel cell power plant (110). Inlet oxidant (38), typically air, required by a catalytic hydrogen processor (34) in a fuel processor (14) for a fuel cell stack assembly (12) in the power plant (110), may contain contaminants such as SO2 and the like. A cleansing arrangement, which includes an accumulator/degasifier (142, 46) acting as a scrubber, and possibly also a water transfer device (118), receives the inlet oxidant and provides the desired cleansing of contaminants. Water in the water transfer device and in the accumulator/degasifier serves to dissolve the water-soluble contaminants and cleanse them from the oxidant stream. The cleansed oxidant stream (138?) is then delivered to the hydrogen processor and to the fuel cell assembly, with minimal inclusion of detrimental contaminants such as sulfur.

Abstract: The heat from various portions of a fuel cell power plant (110) are redistributed in a manner allowing desired modification of/to the heat removal means (152,156), e. g., radiator (152), included in the coolant loop for the fuel cell stack assembly (CSA) (12). A humidifier (70) added in the coolant loop (114) and the inlet oxidant (air) stream (134?) serves to relatively increase the humidification of the inlet air while removing heat from the coolant prior to entering the CSA (12). The combined effects are to relatively increase the temperature of the coolant exiting the CSA without similarly increasing the temperature of the coolant entering the CSA, and to relatively increase the temperature differential (“pinch”) between the coolant entering the heat removal means and the cooling air of the heat removal means (152, 156). This latter effect permits a relative reduction in the size/capacity of the heat removal means (152, 156).

Abstract: Method and apparatus are provided for removing contaminants from a hydrogen processor feed stream, as in a fuel cell power plant (110). Inlet oxidant (38), typically air, required by a catalytic hydrogen processor (34) in a fuel processor (14) for a fuel cell stack assembly (12) in the power plant (110), may contain contaminants such as SO2 and the like. A cleansing arrangement, which includes an accumulator/degasifier (142, 46) acting as a scrubber, and possibly also a water transfer device (118), receives the inlet oxidant and provides the desired cleansing of contaminants. Water in the water transfer device and in the accumulator/degasifier serves to dissolve the water-soluble contaminants and cleanse them from the oxidant stream. The cleansed oxidant stream (138?) is then delivered to the hydrogen processor and to the fuel cell assembly, with minimal inclusion of detrimental contaminants such as sulfur.

Abstract: A fuel processing system (FPS) (110) is provided for a fuel cell power plant (115) having a fuel cell stack assembly (CSA) (56). A water gas shift (WGS) reaction section (12, 120) of the FPS (110) reduces the concentration of carbon monoxide (CO) in the supplied hydrocarbon reformate, and a preferred oxidation (PROX) section (40) further reduces the CO concentration to an acceptable level. The WGS section (12, 120) includes a reactor (124) with a high activity catalyst for reducing the reformate Co concentration to a relatively low level, e.g., 2,000 ppmv or less, thereby relatively reducing the structural volume of the FPS (110). The high activity catalyst is active at temperatures as low as 250° C., and may be a noble-metal-on-ceria catalyst of Pt and Re on a nanocrystaline, cerium oxide-based support. Then only a low temperature PROX reactor (46) is required for preferential oxidation in the FPS (110).

Abstract: Fuel mixing control arrangements are provided for fuel cell power plants (10) operating on multiple fuels (22, 24, 26). A fuel delivery system (16) supplies hydrogen-rich fuel (20) to the cell stack assembly (CSA) (12) after controlled mixing of a primary fuel (22) and at least a secondary fuel (24), each having a respective “equivalent hydrogen (H2) content”. The relative amounts of the primary fuel (22) and secondary fuel (24) mixed are regulated (18, 34, 36) to provide at least a minimum level (LL) of hydrogen-rich fuel having an equivalent hydrogen content sufficient for normal operation of the CSA (12). The primary fuel (22) is a bio-gas or the like having a limited, possibly variable, equivalent H2 content, and the secondary fuel (22) has a greater and relatively constant equivalent H2 content and is mixed with the primary fuel in an economic, constant relationship that assures adequate performance of the CSA (12). One or more parameters (IDC, P, V, E. C.

Abstract: A shift converter, or reactor, (16HT, 16LT) in a fuel processing subsystem (14, 16HT, 16LT, 18), as for a fuel cell (12), uses an improved catalyst bed (34, 50) and the addition of oxygen (40, 40A, 40B, 40C, 40D, 41A, 41B, 41C, 41D) to reduce the amount of carbon monoxide in a process gas stream. The catalyst of bed (34, 50) is a metal, preferably a noble metal, having a promoted support of metal oxide, preferably ceria and/or zirconia. A water gas shift reaction converts carbon monoxide to carbon dioxide. The oxygen may be introduced as air, and causes an improvement in carbon monoxide removal. Use of the added oxygen enables the shift reactor (16HT, 16LT) and its catalyst bed (34, 50) to be relatively more compact for performing a given level of carbon monoxide conversion. The catalyst bed (34, 50) obviates the requirement for prior reducing of catalysts, and minimizes the need to protect the catalyst from oxygen during operation and/or shutdown.

Abstract: A control method and arrangement (48, 50, 150, I, T, P, FFL) are provided in a fuel cell power plant (10) for regulating (48, FC) fuel flow to a steam-based fuel processing system (FPS) (14) associated with a low-temperature fuel cell stack assembly (12). A portion of the fuel provided by the FPS (14) is used to provide steam for the FPS. The fuel flow to the FPS is regulated as a function of the power demand (I) on the fuel cell (12) and at least the enthalpy of the steam (P, T), such that the steam enthalpy is regulated to meet increases and decreases in power demand without exceeding steam pressure limits. In addition to reliance on-steam pressure (P) as a fundamental measure of steam enthalpy, the control may additionally use reaction temperature (T) at, or in, a reformer, such as a catalytic steam reformer (132), to regulate fuel flow and thus, steam enthalpy.

Abstract: A keep warm system for a fuel cell, power plant (10), typically of the PEM type, prevents freeze-sensitive portions of the power plant, such as the cell stack assembly (CSA) (12) and the water management system (28, 30), from freezing under extreme cold external temperatures, during extended storage (CSA shut-down) periods. Pre-stored and pressurized fuel, typically hydrogen (25), normally used to fuel the anode (16) of the CSA, is used as fuel for a catalytic oxidation reaction at a catalytic burner (66) to produce heated gas that convectively passes in heat exchange relation with the freeze sensitive portions (12, 28, 30) of the power plant (10). The convective flow of the heated gases induces the air flow to the burner (66), obviating the need for parasitic electrical loads.

Abstract: A site management system (11) is provided for a power system (8) at site in a utility distribution grid (10). The power system (8) includes multiple fuel cell power plants (18) and one or more loads (14), for selective connection/disconnection with the grid (10) The site management system (11) controls the power plants (18) in an integrated manner, alternatively in a grid connected mode and a grid independent mode. The multiple power plants (18) at the site may be viewed and operated as a unified distributed resource on the grid (10). The site management system (11) provides signals representative of the present power capability (Kw Capacity—88) of each of the power plants (18), and a signal (Total Kw Capacity—95) representative of the total present power capability at the site. These power representations are used to appropriately assign power dispatch loadings to the respective fuel cells (18) in the grid connected mode and in the grid independent mode, and may also be used for load shedding.

Abstract: A power system (8) is provided for economically supplying uninterrupted electrical power to one or more critical loads (14). One or more fuel cell power plants (18) provide one substantially continuous source of power, and a utility grid (10) provides another source of power. The fuel cell power plants (18) are adapted to be, and are, normally substantially continuously connected and providing power to, the critical load(s) (14). A rapidly-acting static switch (19) selectively connects and disconnects and reconnects the grid power supply (10) to the critical load(s) (14) and with the fuel cell power plant(s) (18) for abnormal and normal grid operation, respectively. A switch controller (49, 45) controls the state of the static switch (19) to connect the grid power source (10) with the critical load(s) (14) and the rapidly (less than 4 ms) make the disconnections and the reconnections.

Abstract: A site management system (11) is provided for a power system (8) at site in a utility distribution grid (10). The power system (8) includes multiple fuel cell power plants, e.g., fuel cells, (18) and one or more loads (14), for selective connection/disconnection with the grid (10). The site management system (11) controls the power plants (18) in an integrated manner, alternatively in a grid connected mode and a grid independent mode. The multiple power plants (18) at the site may be viewed and operated as a unified distributed resource on the grid (10). The site management system (11) provides signals representative of the present power capability (Kw Capacity—88) of each of the power plants (18), and a signal (Total Kw Capacity—95) representative of the total present power capability at the site.