Abstract: A technique that is usable with a fuel cell stack includes flowing a fluid through the fuel cell stack to remove thermal energy from the stack. The technique includes flowing the fluid through an expander to produce electrical power.

Abstract: Fuel cell systems and methods are disclosed, where the systems include a burner configured to receive a first gas that is exhausted from a fuel cell and to combust the first gas to provide a second gas, and a heat exchanger in fluid communication with the burner, the heat exchanger being configured to receive the second gas from the burner and to transfer heat from the second gas to additional first gas that is exhausted from the fuel cell.

Abstract: We disclose a system that includes a fuel cell which during operation exhausts a fluid composition that includes an acid or a derivative of the acid, and an acid trap arranged to receive the fluid composition and configured to reduce a concentration of the acid or the derivative of the acid in the fluid composition.

Abstract: A technique that is usable with a fuel cell stack includes combining a fuel flow with an oxidant in a mixer to create a substantially funnel-shaped flow, which is ignited.

Abstract: Fuel cell system reformers for converting an input fluid to a reformate for a fuel cell is disclosed, where the reformers include: (a) a first heat exchanger configured to heat input fluid from a first input fluid temperature Ti1 to a second input fluid temperature Ti2, and to cool reformate from a first reformate temperature Tr1 to a second reformate temperature Tr2; (b) a second heat exchanger configured to heat input fluid from a third input fluid temperature Ti3 to a fourth input fluid temperature Ti4, and to cool an intermediate fluid from a first fluid temperature Tf1 to a second fluid temperature Tf2; and (c) a reactor configured to receive intermediate fluid from the second heat exchanger, to form reformate from intermediate fluid, and to direct reformate to the first heat exchanger.