Abstract: Systems and methods are provided in which ammonia is used as a fuel source for solid oxide fuel cell systems. In the various aspects a high temperature fuel cell stack exhaust stream is recycled through one or more separation or conversion devices to create a purified recycled fuel exhaust stream that is recycled back into the fuel inlet stream of the high temperature fuel cell stack. In various aspects a nitrogen separator may remove nitrogen from the recycled fuel cell stack exhaust stream, a water separator may remove water from the recycled fuel cell stack exhaust stream, and/or an ammonia reactor and hydrogen separator may be used to condition the fuel inlet stream of the high temperature fuel cell stack. In a further aspect a molten carbonate fuel cell and/or Sabatier reactor may be used to condition the fuel inlet stream of the high temperature fuel cell stack.

Abstract: A method of operating a fuel cell electrochemical system includes receiving at least one of a cost of electricity and a cost of fuel and adjusting at least one of an operating efficiency and throughput of the fuel cell based on the at least one of the received cost of electricity and the received cost of fuel.

Abstract: A fuel cell assembly includes a fuel cell stack including a plurality of fuel cells, an incoming oxidizing gas flow path configured to deliver an oxidizing gas to the plurality of fuel cells, and a chromium-getter material located in the incoming oxidizing flow path. A fuel cell includes an electrolyte, a cathode electrode on a first side of the electrolyte, an anode electrode on a second side of the electrolyte, and a chromium-getter material on the cathode electrode.

Abstract: A method of making a metal interconnect for an electrolytic cell stack includes oxidizing the metal interconnect prior to providing the oxidized metal interconnect into the electrolytic cell stack. A pre-oxidized metal interconnect for an electrolytic cell stack would not substantially further oxidize upon exposure to a subsequent oxidizing ambient at a temperature of at least 900° C. prior to or after being provided into the electrolytic cell stack.

Abstract: A method of controlling a fuel cell system includes applying alternating current (AC) signals to an individual fuel cell. The AC signals have a plurality of different frequencies. A voltage across the individual fuel cell is determined at each of the plurality of different frequencies. An impedance characteristic of the individual fuel cell is determined based at least in part on the voltage across the individual fuel cell at each of the plurality of different frequencies. The individual fuel cell is controlled based at least in part on the impedance characteristic.

Abstract: A fuel cell stack includes a plurality of fuel cells, a plurality of interconnects, and a plurality of seal members, wherein the plurality of seal members comprises one or more first seal members and one or more additional seal members, where the one or more first seal members form a protective barrier between the reducing environment contained with the fuel cell stack and the remaining seal members.

Abstract: Methods for refurbishing components, such as interconnects of a fuel cell stack, include singulating the stack and removing the electrolyte, seals and oxide layer using non-mechanical methods. The various methods of may be used either singly or in combination.

Abstract: Various hot box fuel cell system components are provided, such as heat exchangers, steam generator and other components.

Abstract: Systems and methods are provided for fuel cell stack heat treatment. An eductor may be used to recycle air into the air inlet stream or to recycle fuel into the fuel inlet stream. An eductor may also be used to exhaust air away from the furnace. The stack heat treatment may include stack sintering or conditioning. The conditioning may be conducted without using externally supplied hydrogen.

Abstract: Methods for refurbishing components, such as interconnects of a fuel cell stack, include singulating the stack and removing the electrolyte, seals and oxide layer using non-mechanical methods. The various methods of may be used either singly or in combination.

Abstract: A fuel purification system includes a fuel cell stack and a fuel purification unit, such as a distillation unit. The fuel cell stack is adapted to provide heat to the fuel purification unit, and the fuel purification unit is adapted to provide a purified fuel to the fuel cell stack.

Abstract: An interconnect for a fuel cell stack includes a first set of gas flow channels in a first portion of the interconnect, and a second set of gas flow channels in second portion of the interconnect. The channels of the first set have a larger cross sectional area than the channels of the second set.

Abstract: A system and method in which a high temperature fuel cell stack exhaust stream is recycled back into the fuel inlet stream of the high temperature fuel cell stack. The recycled stream may be sent to a carbon dioxide separation device which separates carbon dioxide from the fuel exhaust stream. The carbon dioxide separation device may be a carbon dioxide trap, an electrochemical carbon dioxide separator, or a membrane separator. A water separator may be used in conjunction with the carbon dioxide separation device or used separately to continuously remove water from the recycled stream.

Abstract: Various embodiments provide methods and systems for detecting cracks in ceramic electrolytes using electrical conductors. A method for testing an electrolyte material, such as a ceramic electrolyte material for use in a solid oxide fuel cell device, includes providing a conductive path on the electrolyte material, electrically connecting a probe across the conductive path, and measuring a value associated with the conductive path to determine the presence or absence of a crack in the material.

Abstract: A method of operating a fuel cell electrochemical system includes receiving at least one of a cost of electricity and a cost of fuel and adjusting at least one of an operating efficiency and throughput of the fuel cell based on the at least one of the received cost of electricity and the received cost of fuel.

Abstract: An interconnect for a fuel cell stack includes a first set of gas flow channels in a first portion of the interconnect, and a second set of gas flow channels in second portion of the interconnect.

Abstract: A fuel purification system includes a fuel cell stack and a fuel purification unit, such as a distillation unit. The fuel cell stack is adapted to provide heat to the fuel purification unit, and the fuel purification unit is adapted to provide a purified fuel to the fuel cell stack.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: A method of operating a fuel cell electrochemical system includes receiving at least one of a cost of electricity and a cost of fuel and adjusting at least one of an operating efficiency and throughput of the fuel cell based on the at least one of the received cost of electricity and the received cost of fuel.

Abstract: A fuel purification system includes a fuel cell stack and a fuel purification unit, such as a distillation unit. The fuel cell stack is adapted to provide heat to the fuel purification unit, and the fuel purification unit is adapted to provide a purified fuel to the fuel cell stack.