Abstract: Hemofilters for in vivo filtration of blood are disclosed. The hemofilters disclosed herein provide an optimal flow of blood through the filtration channels while maintaining a pressure gradient across the filtration channel walls to enhance filtration and minimize turbulence and stagnation of blood in the hemofilter.

Abstract: Hemofilters for in vivo filtration of blood are disclosed. The hemofilters disclosed herein provide an optimal flow of blood through the filtration channels while maintaining a pressure gradient across the filtration channel walls to enhance filtration and minimize turbulence and stagnation of blood in the hemofilter.

Abstract: Hemofilters for in vivo filtration of blood are disclosed. The hemofilters disclosed herein provide an optimal flow of blood through the filtration channels while maintaining a pressure gradient across the filtration channel walls to enhance filtration and minimize turbulence and stagnation of blood in the hemofilter.

Abstract: Hemofilters for in vivo filtration of blood are disclosed. The hemofilters disclosed herein provide an optimal flow of blood through the filtration channels while maintaining a pressure gradient across the filtration channel walls to enhance filtration and minimize turbulence and stagnation of blood in the hemofilter.

Abstract: A method for creating an oxygen depleted gas in a fuel cell system, including operating a fuel cell stack at a desired cathode stoichiometry at fuel cell system shutdown to displace a cathode exhaust gas with an oxygen depleted gas. The method further includes closing a cathode flow valve and turning off a compressor to stop the flow of cathode air.

Abstract: A method for forming seals in a fuel cell stack includes a step of screen printing a first sealing layer on a first flow field plate. The first sealing layer defines a first pattern and has a first predetermined sealing layer thickness. A multilayer seal is formed by screen printing a second sealing layer over the first sealing layer. The second sealing layer defines a second pattern and has a second predetermined sealing layer thickness. A third sealing layer is screen printed over a first side of a second flow field plate and has a third predetermined sealing layer thickness. A fourth sealing layer is screen printed over a second side of the second flow field plate having a fourth predetermined sealing layer thickness. The first flow field plate and the second flow field plate are combined to form flow channels for guiding reactants a fuel cell catalyst layers.

Abstract: A system and method for reducing the corrosive effects of an air/hydrogen front in a fuel cell stack. The method includes shutting down the fuel cell stack and then initiating a hydrogen sustaining process where hydrogen is periodically injected into an anode side of the fuel cell stack while the stack is shut down for a predetermined period of time. The method determines that the hydrogen sustaining process has ended, and then purges the anode side and a cathode side of the fuel cell stack with air after the hydrogen sustaining process has ended and the stack is still shut-down.

Abstract: A system and method of producing syngas from a solid waste stream is provided. The system includes a low tar gasification generator that gasifies the solid waste stream to produce a first gas stream. A process module cools the first gas stream and removes contaminants, such as metals, sulfur and carbon dioxide from the first gas stream to produce a second gas stream having hydrogen and carbon monoxide. The second gas stream is received by pressure swing absorber which removes carbon monoxide and increases the purity of the hydrogen to allow the generation of electrical power by a PEM fuel cell in a power module. A water gas shift process may be used to convert carbon monoxide recovered from a retentate stream exhausted by the pressure swing absorber.

Abstract: A system and method of producing electrical power from a solid waste stream is provided. The system includes a low tar gasification generator that receives a feedstock stream, such as a solid waste stream. The feedstock stream is gasified to produce a first gas stream that includes hydrogen, at least one contaminant and at least one diluent. At least one clean-up process is performed on the first gas stream to remove the at least one contaminant and generate a second gas stream. Electrical power is generated by a solid oxide fuel cell in response to receiving the second gas stream. The solid oxide fuel cell outputting an anode exhaust gas stream. A portion of the anode exhaust gas is vented to reduce the level of diluent in the second gas stream.

Abstract: A system and method of producing syngas from a solid waste stream is provided. The system includes a low tar gasification generator that gasifies the solid waste stream to produce a first gas stream. A process module cools the first gas stream and removes contaminants, such as metals, sulfur and carbon dioxide from the first gas stream to produce a second gas stream having hydrogen. The second gas stream may be received by a power module that generates electrical power from the second gas stream. The process module may include one or more heat exchangers. The process module may further increase the pressure of an oxygen gas stream that flows to the gasification generator.

Abstract: A system and method of producing syngas from a solid waste stream is provided. The system includes a low tar gasification generator that gasifies the solid waste stream to produce a first gas stream. A process module cools the first gas stream and removes contaminants, such as metals, sulfur and carbon dioxide from the first gas stream to produce a second gas stream having hydrogen. The second gas stream is received by a power module that generates electrical power from the second gas stream. The process module may include one or more heat exchangers.

Abstract: A bipolar plate assembly for a fuel cell is provided. The bipolar plate assembly includes a first electroformed unipolar plate disposed adjacent a second electroformed unipolar plate. The first and second unipolar plates are bonded by a plurality of localized electrically and thermally conductive plugs by electroplated material deposited within apertures formed in the substrates onto which the unipolar plates are electroformed. A method for forming the bipolar plate assembly is also described.

Abstract: A fuel cell component includes a first fluid distribution layer, a second fluid distribution layer, a cap layer, a third fluid distribution layer, and a pair of fluid diffusion medium layers. The individual layers are polymeric, mechanically integrated, and formed from a radiation-sensitive material. The first fluid distribution layer, the second fluid distribution layer, the cap layer, the third fluid distribution layer, and the pair of fluid diffusion medium layers are coated with an electrically conductive material. A pair of the fuel cell components may be arranged in a stack with a membrane electrode assembly therebetween to form a fuel cell.

Abstract: A method for creating an oxygen depleted gas in a fuel cell system, including operating a fuel cell stack at a desired cathode stoichiometry at fuel cell system shutdown to displace a cathode exhaust gas with an oxygen depleted gas. The method further includes closing a cathode flow valve and turning off a compressor to stop the flow of cathode air.

Abstract: A method for forming seals in a fuel cell stack includes a step of screen printing a first sealing layer on a first flow field plate. The first sealing layer defines a first pattern and has a first predetermined sealing layer thickness. A multilayer seal is formed by screen printing a second sealing layer over the first sealing layer. The second sealing layer defines a second pattern and has a second predetermined sealing layer thickness. A third sealing layer is screen printed over a first side of a second flow field plate and has a third predetermined sealing layer thickness. A fourth sealing layer is screen printed over a second side of the second flow field plate having a fourth predetermined sealing layer thickness. The first flow field plate and the second flow field plate are combined to form flow channels for guiding reactants a fuel cell catalyst layers.

Abstract: A fuel cell stack of at least two fuel cells, each fuel cell having a unitized electrode assembly (UEA) including a membrane electrode assembly (MEA), a sub-gasket and gas diffusion media (DM), and positioned between modified stamped field-flow plates. The sub-gasket frames the MEA resulting in an overlap area between the MEA and the inner perimeter of the sub-gasket. The UEA is disposed between a pair of stamped flow-field plates which align in adjacent fuel cells to form a bipolar plate. The bipolar plate has an active region, an overlap region and a seal region. The active region is configured with channel and land features which provide reactant flow channels and coolant passages for the fuel cell. The configuration of features in the overlap region, however, is modified from the configuration in the active region so that the overlap region may sustain sufficient mechanical sealing pressure, and to prevent coolant and reactant bypass without impeding coolant and reactant flow in the active area.

Abstract: Methods for starting a fuel cell system are provided. In one embodiment, the method includes providing hydrogen to an inlet of an anode of the fuel cell pressurizing the anode to a pressure; determining whether a blocked cell condition exists; if a blocked cell condition exists, if no blocked cell condition exists, initiating a normal start sequence, alternately reducing the pressure of the anode and increasing the pressure of the anode until an exit condition exists, the exit condition selected from a voltage of the fuel cell being stable, or a temperature of the fuel cell being greater than about 0° C., or both, and when the exit condition exists, initiating the normal start sequence.

Abstract: A fuel cell stack assembly is disclosed that includes a porous member disposed within a flow path for a reactant. A fluid collection member is provided within the flow path adjacent to and in fluid communication with the porous member. The porous member and the fluid collection member cooperate to collect liquid water from the reactant flowing in the flow path, wherein the collected liquid water may be drained from the fluid collection member.

Abstract: A detection method for enabling gas composition observation during fuel cell system start-up is described. In one embodiment, the method includes initiating a flow of hydrogen to the anode to pressurize the anode; opening an anode flow valve; determining if an anode pressure exceeds an anode pressure threshold; enabling anode flow set point detection after a first predetermined time if the anode pressure exceeds the anode pressure threshold; monitoring an anode flow set point using the anode flow set point detection; determining if the anode flow set point exceeds an anode flow set point threshold; and closing the anode flow valve after a second predetermined time if the anode flow set point exceeds the anode flow set point threshold.

Abstract: A fuel cell stack assembly is disclosed that includes a porous member disposed within a flow path for a reactant. A fluid collection member is provided within the flow path adjacent to and in fluid communication with the porous member. The porous member and the fluid collection member cooperate to collect liquid water from the reactant flowing in the flow path, wherein the collected liquid water may be drained from the fluid collection member.