Abstract: Described herein are catalytic heating systems comprising self-heated catalytic reactors and methods of operating thereof. A self-heated catalytic reactor comprises a corrugated conductive layer and an insulator layer forming a stack (e.g., a wound stack) such that each pair of adjacent conductive layers in the stack is separated by an insulator layer. The self-heated catalytic reactor also comprises a catalyst layer, positioned on one or both conductive and insulator layers, and two electrodes electrically coupled to the conductive layer at the opposite ends. The catalyst layer is preheated by passing an electric current through the two electrodes and resistively heating the conductive layer, in some examples, supporting at least a portion of the catalyst layer. This internal heating reduces the time and energy required to bring the catalyst layer to its operating temperature, at which point the fuel can be introduced to provide additional heating.

Abstract: Described herein are solid oxide fuel cells (SOFCs), comprising anode-conductor seals and/or cathode-conductor seals used for sealing porous metal structures and controlling the distribution of fuel and oxidants within these porous structures. For example, a SOFC comprises an anode conductor, cathode conductor, and electrolyte, disposed between the anode and cathode conductors. The anode conductor comprises multiple porous portions (permeable to the fuel) and a non-porous portion. The SOFC also comprises an anode-conductor seal, forming a stack with the non-porous portion. This sealing stack extends between the electrolyte and current collector and separates two porous portions thereby preventing the fuel and oxidant migration between these portions. In some examples, the sealing stack forms an enclosed boundary around one porous portion of the anode conductor. In the same or other examples, another sealing stack is formed in the cathode conductor, e.g.

Abstract: Described herein are catalytic heating systems, comprising catalytic reactors and dual-mode fuel evaporators, and methods of operating such systems. A dual-mode fuel evaporator is thermally coupled to a catalytic reactor and comprises an electric heater used for preheating the evaporator to at least a fuel-flow threshold temperature. Upon reaching this threshold, the liquid fuel, such as ethanol or methanol, is flown into the evaporator and evaporates therein, forming vaporized fuel. The vaporized fuel is mixed with oxidant, and the mixture is flown into the catalytic reactor where the vaporized fuel undergoes catalytic exothermic oxidation. At least some heat, generated in the catalytic reactor, is transferred to the evaporator and used for the evaporation of additional fuel. When the evaporator reaches or exceeds its operating threshold, the electric heater can be turned off and all heat is supplied to the evaporator from the catalytic reactor.

Abstract: Described herein are catalytic heating systems, comprising catalytic reactors and dual-mode fuel evaporators, and methods of operating such systems. A dual-mode fuel evaporator is thermally coupled to a catalytic reactor and comprises an electric heater used for preheating the evaporator to at least a fuel-flow threshold temperature. Upon reaching this threshold, the liquid fuel, such as ethanol or methanol, is flown into the evaporator and evaporates therein, forming vaporized fuel. The vaporized fuel is mixed with oxidant, and the mixture is flown into the catalytic reactor where the vaporized fuel undergoes catalytic exothermic oxidation. At least some heat, generated in the catalytic reactor, is transferred to the evaporator and used for the evaporation of additional fuel. When the evaporator reaches or exceeds its operating threshold, the electric heater can be turned off and all heat is supplied to the evaporator from the catalytic reactor.

Abstract: Described herein are solid oxide fuel cells (SOFCs), comprising anode-conductor seals and/or cathode-conductor seals used for sealing porous metal structures and controlling the distribution of fuel and oxidants within these porous structures. For example, a SOFC comprises an anode conductor, cathode conductor, and electrolyte, disposed between the anode and cathode conductors. The anode conductor comprises multiple porous portions (permeable to the fuel) and a non-porous portion. The SOFC also comprises an anode-conductor seal, forming a stack with the non-porous portion. This sealing stack extends between the electrolyte and current collector and separates two porous portions thereby preventing the fuel and oxidant migration between these portions. In some examples, the sealing stack forms an enclosed boundary around one porous portion of the anode conductor. In the same or other examples, another sealing stack is formed in the cathode conductor, e.g.

Abstract: Described herein are solid oxide fuel cells comprising conductive layers and methods of fabricating such cells. Specifically, a solid oxide fuel cell comprises cathode and anode layers, each comprising a porous base, catalyst sites disposed within the base, and a conductive layer. The conductive layer provides electrical conduction between the corresponding current collector and the catalyst sites. The conductive layer may at least partially extend into the porous base. For example, at least a portion of the conductive layer may be formed by infiltration of the porous base, e.g., before catalyst infiltration. In some examples, at least a portion of the conductive layer forms an interface between the corresponding porous base and the current collector. In these examples, the conductive layer is formed from an initial (green) conductive layer that is stacked between layers used to form the porous base and current collector and sintered the stack.

Abstract: Described herein are two-stage catalytic heating systems and methods of operating thereof. A system comprises a first-stage catalytic reactor and a second-stage catalytic reactor, configured to operate in sequence and at different operating conditions, For example, the first-stage catalytic reactor is supplied with fuel and oxidant at fuel-rich conditions. The first-stage catalytic reactor generates syngas. The syngas is flown into the second-stage catalytic reactor together with some additional oxidant. The second-stage catalytic reactor operates at fuel-lean conditions and generates exhaust. Splitting the overall fuel oxidation process between the two catalytic reactors allows operating these reactors away from the stoichiometric fuel-oxidant ratio and avoiding excessive temperatures in these reactors. As a result, fewer pollutants are generated during the operation of two-stage catalytic heating systems. For example, the temperatures are maintained below 1.000° C. at all oxidation stages.