Ballard Power Systems Corporation

Ballard Generation Systems Inc.

Craig Louie

David S Watkins

Richard F Buswell

Joseph V Clausi

Michael Eiche

Ryan Cownden

Ronald Cohen

A fuel cell electric power generation system includes an electric power generation subsystem, a fuel processing subsystem including a furnace, an oxidant subsystem, a water circulation subsystem, and a temperature control subsystem. Interactions between the subsystems are simplified and component integration improves thermal and electrical efficiency of the system. In one embodiment, a reformer, a fuel stream humidifier and a heat exchanger are disposed within the furnace, with the humidifier outlet fluidly connected to the reformer inlet and the heat exchanger outlet fluidly connected to a desulfurizer located outside of the furnace. The fuel processing subsystem can also include a shift reactor that exchanges heat with a cathode exhaust stream directed to the shift reactor from the power generation subsystem. After passing through the shift reactor, the cathode exhaust stream is preferably directed to the furnace burner.

Fuel cell electric power generation system

A fuel cell electric power generation system comprises an electric power generation subsystem, a fuel processing subsystem, an oxidant subsystem, a water circulation subsystem, and a temperature control subsystem. The improved system employs a novel arrangement of components which provides improved interaction between the subsystems while also simplifying the apparatus by integrating components to provide improved thermal and electrical efficiency. The fuel processing subsystem preferably comprises a furnace for providing heat to a plurality of components disposed within the furnace. In one embodiment, a reformer, a fuel stream humidifier, and a heat exchanger are all disposed within the furnace vessel, with the outlet of the humidifier fluidly connected to the inlet of the reformer and the outlet of the heat exchanger fluidly connected to a desulfurizer located external to the furnace. The fuel processing subsystem may further comprise a shift reactor that exchanges heat with a cathode exhaust stream directed to the shift reactor from the power generation subsystem. After passing through the shift reactor, the cathode exhaust stream is preferably directed to the furnace burner.

A method and apparatus are provided for reducing the concentration of carbon monoxide in a gaseous reactant stream comprising carbon monoxide and water vapor. The catalyst bed of a water gas shift reactor is preferably divided into two sections. Alternatively, an assembly which includes two sequential reactors can be employed. The first section or reactor operates in an adiabatic fashion whereas the second section or reactor is cooled, thereby facilitating the further conversion of carbon monoxide in the second section or reactor. The gaseous reactant stream exiting the second section or reactor typically has a carbon monoxide concentration in the range from about 0.06% to about 0.14% by volume.

Two-stage water gas shift conversion method

A power plant system produces utility grade electrical AC power from gaseous or liquid hydrocarbon fuels using a fuel cell stack employing ion exchange membranes. The fuel is desulfurized, mixed with water, heated and vaporized before being introduced into a reformer. The reformer produces a hydrogen-rich gas which is then directed through a series of heat exchangers, shift converters and a selective oxidizer. The processed fuel stream is combined in the fuel cell stack with a pressurized oxidant stream to generate DC power. Oxidant pressure is supplied by compressors driven by turbines using heated system exhaust gases. The DC power is converted into utility grade AC power using an inverter augmented by a battery peaking unit for rapid load following. The water generated in the fuel cell stack is recycled and used to cool the fuel cell stack and to humidify the fuel stream and oxidant stream prior to their introduction to the fuel cell stack. System integration results in an electrical efficiency of at least about 40%, and with heat recovery the overall fuel efficiency is greater than approximately 80%.

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Vancouver, Canada

Craig Louie