A hybrid redox fuel cell system includes a hybrid redox fuel cell and an electrochemical cell. The hybrid redox fuel cell includes an anode side through which hydrogen is flowed and a cathode side through which liquid electrolyte is flowed, the liquid electrolyte including a metal ion at a higher oxidation state and the metal ion at a lower oxidation state. An anode side of the electrochemical cell is fluidly connected to the cathode side of the hybrid redox fuel cell. At the hybrid redox fuel cell, power is generated by reducing the metal ion at the higher oxidation state to the lower oxidation state at the cathode side while oxidizing the reductant at the anode side. At the anode side of the electrochemical cell, the metal ion at the lower oxidation state is oxidized to the higher oxidation state while the power is generated.

A hybrid redox fuel cell system includes a hybrid redox fuel cell including an anode side through which a reductant is flowed and a cathode side through which liquid electrolyte is flowed, and a trickle bed reactor including a catalyst bed fluidly connected to the cathode side of the hybrid redox fuel cell. Furthermore, the liquid electrolyte includes a metal ion at a higher oxidation state and the metal ion at a lower oxidation state, and power is generated at the hybrid redox fuel cell by way of reducing the metal ion at the higher oxidation state to the lower oxidation state at the cathode side while oxidizing the reductant at the anode side.

The present invention relates to a power supply system for underwater vehicles, in particular to a power supply system for autonomous underwater vehicles, to underwater vehicles equipped with such power supply systems and to a method of operating an underwater vehicle. The power supply system for underwater vehicles comprises a hydrogen fuel cell, which on the one hand is in fluid contact with a metal hydride storage tank, and on the other hand, with a membrane module that is capable of extracting dissolved oxygen from water. By combining the above mentioned components, the energy necessary to support the AUV operation and the operation of its sensors can be provided, replacing in an efficient and sustainable way the currently employed battery energy systems. For the operation of gliders, a weight compensating mechanism could also be implemented.

A controller for a fuel cell based power generator includes a memory and a processor configured to execute executable instructions stored in the memory to receive a pressure in an anode loop of the fuel cell based power generator, wherein the anode loop includes a hydrogen generator and an anode loop blower, and control the anode loop blower such that the hydrogen generator provides hydrogen to an anode of a fuel cell via the blower and the anode loop at a controlled pressure. In further embodiments, the temperatures of the fuel cell and hydrogen generator are independently controlled.

A method of cleansing a redox flow battery system may include operating the redox flow battery system in a charge, discharge, or idle mode, and responsive to a redox flow battery capacity being less than a threshold battery capacity, mixing the positive electrolyte with the negative electrolyte. In this way, battery capacity degradation following cyclic charging and discharging of the redox flow battery system can be substantially reduced.

A waste reduction system that utilizes organic solids suspended in a waste stream to produce carboxylic acids, which can then be employed as an input to a microbial fuel cell or other biological processes to further enhance biogas production, is provided. The organic waste stream influent undergoes a multistage fermentation process in which fermentative microorganism metabolize the organic waste materials and produce one or more carboxylic acids, especially short chain fatty acids. The carboxylic acids serve as a food source for bacteria within an anode compartment of an MFC that generates useable electricity therefrom.

A waste reduction system that utilizes organic solids suspended in a waste stream to produce carboxylic acids, which can then be employed as an input to a microbial fuel cell or other biological processes to further enhance biogas production, is provided. The organic waste stream influent undergoes a multistage fermentation process in which fermentative microorganism metabolize the organic waste materials and produce one or more carboxylic acids, especially short chain fatty acids. The carboxylic acids serve as a food source for bacteria within an anode compartment of an MFC that generates useable electricity therefrom.

A fuel cell module includes a first area where an exhaust gas combustor and a start-up combustor are provided, an annular second area around the first area where a heat exchanger is provided, an annular third area around the second area where a reformer is provided, an annular fourth area around the third area where an evaporator is provided. The heat exchanger includes heat exchange pipes connected to an oxygen-containing gas supply chamber and an oxygen-containing gas discharge chamber. A first circumscribed non-uniform flow suppression plate is provided along a minimum circumscribed circle which contacts outer surfaces of the heat exchange pipes.

A hydrogen generator, a fuel pellet assembly for use in the hydrogen generator and a fuel cell system are disclosed. The hydrogen generator includes a housing having a lid pivotally connected to a base and a strip having a plurality of heaters on one side and a second plurality of heaters on the opposite side. A first cartridge is disposed on one side of the strip and a second cartridge is disposed on the opposite side. Each of the first and second cartridges has a plurality of fuel pellets, each including a hydrogen-containing material that will release hydrogen gas when heated. The heaters are selectively activated to heat one or more fuel pellets to initiate the release of hydrogen gas.

A geothermal heat extractor includes a heat transfer fluid and a heat transfer fluid supply conduit. The heat transfer fluid is maintained in the supply conduit in a liquid state at a pressure above its saturation pressure. The geothermal heat extractor further includes a heat transfer fluid return conduit, a geothermal heat source coupled thereto, at least one flow control valve configured to control the flow of the heat transfer fluid from the supply conduit to the return conduit, and an external load coupled to the return conduit. As the heat transfer fluid is provided to the return conduit in the liquid state, the heat transfer fluid vaporizes in the return conduit by heat supplied to the return conduit from the geothermal heat source. The vaporized heat transfer fluid is supplied from the return conduit to the external load.