Abstract: Methods and apparatus for improving water management in a PEM fuel cell power supply are disclosed. The fuel cell power supply includes a combustion unit that combusts anode exhaust, producing combusted exhaust that includes water. The combusted exhaust is recycled to the anode input and/or the cathode input. The recycling system can include additional devices, for example, a CO removal device for removing CO from the combusted exhaust prior to recycling to the anode. A fuel processor can be thermally coupled to the combustion unit that combusts the anode exhaust. One advantage of the invention is that the condenser typically employed for recovering water from combusted exhaust can be eliminated, of reduced capacity or operated less frequently, thereby reducing the cost and/or the complexity of the fuel cell power supply.

Abstract: A water transport plate is provided with optimized physical characteristics to greatly improve fuel cell operation. In a preferred method of manufacturing, graphite powder, reinforcing fibers, cellulosic fibers, and a thermosetting resin are mixed with a liquid to form a slurry and showered onto a screen to form a planar sheet which is dried to form paper. The paper is cut into the desired size and is laid-up. The lay-up is laminated with pressure and heat, carbonized, and graphitized to form a water transport plate for later machining as desired. The finished water transport plate exhibits optimal physical characteristics for bubble pressure, water permeability, median pore size, porosity, thru-plane resistivity and compressive yield strength.

Abstract: A fuel cell (10), having a proton exchange membrane (48), an anode and a cathode, and cathode and anode water transport plates (12, 16), includes a water capillary edge seal to optimize and greatly improve fuel cell operation without the need for additional seals or impregnation of the water transport plates. The water filled porous bodies of the water transport plates (12, 16) use the capillary forces of the water, which is a product of the electrochemical reaction of the fuel cell (10) and the preferred coolant, to prevent gas intrusion into the water system and over board leakage of the gases as well as the resultant hazardous mixture of gaseous fuel and oxidizing gas.

Abstract: An alcohol and water recovery system for a direct aqueous alcohol fuel cell power plant includes at least one direct aqueous alcohol fuel cell for producing electrical energy, and a direct alcohol and water transfer device for recovering alcohol and water leaving the plant and transferring the recovered alcohol and water back into the plant. The direct alcohol and water transfer device passes a process oxidant stream upstream of the plant in mass transfer relationship with a plant exhaust stream that includes aqueous alcohol fuel and process oxidant fluid streams that have passed through the fuel cell, so that alcohol and water in the plant exhaust stream transfer directly through a mass transfer medium of the device to the process oxidant stream entering the fuel cell. The device includes a separator housing for supporting the transfer medium and for preventing bulk mixing of the streams.

Abstract: During start up, a fuel cell is warmed to operating temperature by introducing a dilute hydrogen/air mixture into the normal process oxidant channels of the fuel cell where it reacts with a noble metal or noble metal alloy catalyst to produce heat at subflame temperatures. In one embodiment, catalyst is provided in a structure between the cathode and the process oxidant channels; if the structure is not sufficiently hydrophobic to allow the hydrogen/fuel mixture to reach it, such structure may be specially produced with hydrophobic regions to assure ice-free passages; in a structure with sufficient hydrophobic regions, only the catalyst need be added. In embodiments with a hydrophobic cathode, no structural modification is required; or a hydrophilic cathode may be provided with hydrophobic regions.

Abstract: Method and apparatus for changing the state of operation of a fuel cell, such as starting the fuel cell up or shutting the fuel cell down, are disclosed. An idle load is applied to the fuel cell when the cell temperature is between about normal operating temperature and a transition temperature, and fuel and oxidizer are supplied to the fuel cell commensurate with the power delivered to the idle load. Below the transition temperature, purging/passivation procedures known in the art can be followed, and an open or dummy load applied to the fuel cell. At normal operating temperature or above a service load is applied to the fuel cell.

Abstract: A control system and method for controlling a fuel processing system operational to produce a gas for a downstream process from a fuel, wherein the fuel processing system uses a plurality of fuel processing elements, a fuel input and a waste gas input, each of the fuel processing elements having an individual output and the plurality of fuel processing elements having a collective output, and wherein the downstream process has a waste gas output and a dynamic gas load demand. The control system includes a device for receiving communication from the downstream process indicative of the dynamic load demand and a device for controlling the collective output level of the gas in response to the dynamic load demand.

Abstract: The end plate assemblies in a fuel cell stack are conductive and made from metal that is susceptible of corroding in the hostile fuel cell environment. Coolant fluid circulates through these plates. Reactants must also be fed through the end plate assemblies plate. The reactant and coolant fluids are delivered through manifolds that communicate with each cell. Savings in weight and improvements in corrosion resistance are achieved by fabricating headers for these pressure plates of polymeric material. Each header has fluid inlet or outlet ports and internal passageways that communicate with passageways in the cell assemblies located between the metal pressure plates.

Abstract: An improved electrochemical cell such as a fuel cell is disclosed including a porous support plate for enhancing transport of fluids throughout the cell and for enhancing capacitance and transient response capability of the cell. The electrochemical cell includes an electrolyte having opposed major surfaces with an anode and a cathode electrode supported in intimate contact with the opposed major surfaces. A porous support plate is secured adjacent each electrode, and each porous support plate includes a contact bi-layer in intimate contact with the electrode. Each contact bi-layer is comprised of a hydrophobic phase including a mixture of carbon black and a hydrophobic polymer defining a network of hydrophobic gas passages and each contact bi-layer also includes a hydrophilic phase including a mixture of carbon black and a proton exchange resin defining a network of hydrophilic liquid passages integrated throughout the contact bi-layer.

Abstract: A mass and heat recovery system for a fuel cell power plant includes at least one fuel cell for producing electrical energy, hydrocarbon fuel processing components for producing a hydrogen rich reducing fluid for the fuel cell, and a direct mass and heat transfer device for recovering mass and heat such as water vapor leaving the plant. The fuel processing components include an auxiliary burner that provides heat to generate steam and a reformer that receives the steam mixed with a hydrocarbon fuel along with a small amount of air and converts the mixture to a hydrogen rich stream appropriate for supplying hydrogen to the anode electrode.

Abstract: An improved porous support layer is disclosed for use in an electrochemical cell such as a fuel cell having a proton exchange membrane ("PEM") as an electrolyte. In a preferred embodiment the porous support layer is positioned near and in fluid communication with an electrode to facilitate fluid transport to and away from each electrode. Each such porous support layer includes hydrophobic pores and hydrophilic pores integrated throughout the layer, wherein the hydrophobic pores are coated with a hydrophobic substance and include about 75 percent to about 95 percent of the total pore volume of the porous support layer, and the hydrophilic pores comprise about 25 percent to about 5 percent of the total pore volume of the porous support layer. The hydrophobic pores of the porous support layers facilitate gas transfer and restrict liquid water absorption into the hydrophobic pores, while the hydrophilic pores facilitate simultaneous liquid water transport through the layers.

Abstract: The present invention is directed to a water separator for separating a two-phase stream into a liquid water component and a gas component. The water separator includes a housing defining a cavity and includes an input port, a gas output port and a water output port. A hydrophobic filter is provided in the cavity and interposed between the input port and the gas output port so as to prevent a liquid water component of a two-phase stream of gas and water entering the input port from exiting the gas output port. A hydrophilic filter is provided in the cavity and interposed between the input port and the water output port so as to prevent the gas component entering the input port from exiting the water output port.

Abstract: A system for generating a desired output gas from an input fuel for use in a downstream process is disclosed. The system includes a plurality of fuel processing units to generate the desired output gas, wherein each of the plurality of fuel processing units includes a reformer which uses waste gas output from the downstream process to facilitate the processing of the fuel. Each of the fuel processing units is operational over a range up to full capacity, wherein the plurality of fuel processing units are interconnected in an collective operating scheme to process the fuel. A control system is provided for controlling the plurality of fuel processing units in response to requirements of a dynamic load demand from the downstream operation. The control system is operative to adjust the operational level of each of the plurality of fuel processing units to produce individual responses from each of the fuel processing units.

Abstract: The present invention discloses a method for preparing a catalyst to be applied to an electrode substrate, the method incorporates cooling the catalyst material to a temperature below a critical temperature and grinding the cooled catalyst to produce a catalyst material which will create a uniform catalytic layer on an electrode substrate. The finished electrode having significantly fewer particles than the electrode prepared by the prior art method.

Abstract: The present invention discloses a transport frame for transporting and maintaining a fuel cell stack assembly in a fixed position. The fuel cell stack asembly which is under compression by a top and bottom plate held together by tie rods positioned at the corners of each plate. The top and bottom plates are then mounted to a rigid frame for transporting the fuel cell. The tie rods being attached to mounts in the base plate of the rigid frame and an insulated attachment between the top plate of the fuel cell stack frame and the rigid frame is made. The fuel cell stack assembly being electrically insulated from the rigid frame.

Abstract: The reactant flow field on the cathode side of a fuel cell assembly is formed from a plate made from carbon particles that are bonded together by a fluorocarbon polymer binder. The cathode reactant flow field is non-porous, and is hydrophobic due to the presence of the poller binder. The carbon particles are preferably carbon flakes which pack together very tightly, and require only a minor amount of the polymer binder to form a solid plate. The plate will provide cathode reactant flow channels, will conduct electrons and heat and will minimize acid absorption in a fuel cell stack due to its hydrophobic nature.

Abstract: A fuel cell component that includes a porous fuel cell plate and a solid frame contiguously extending all around the fuel cell plate is made by first forming an integral plate-shaped porous body including a central portion constituting the fuel cell plate and a peripheral portion integral with and circumferentially completely surrounding the central portion, and then impregnating the pores of only the peripheral portion with a quantity of initially flowable but solidifiable impregnating material such that the impregnating material is accommodated in and completely fills such pores and makes the peripheral portion solid and completely fluid-impermeable upon solidification of the impregnating material to constitute the frame.

Abstract: The integrated apparatus includes within a single vessel a plurality of components for processing fuel in a fuel cell plant. Along with the gas reformer is an air preheater for the burner and a plenum for supplying the shift converter. The shift converter is also in the vessel with upstream steam and fuel heat exchangers. The shift converter heat exchanger is also included.

Abstract: During operation of a fuel cell stack, electrolyte within individual fuel cells migrates between the cathode side and the anode side, and across the separator plate between the cathode side and the anode side electrolyte reservoir plate of a second cell. An electrochemical sensor comprised of wires, a sheath, and a porous conduit having a pore size distribution which is similar to that of the electrolyte reservoir plate in which the electrochemical sensor is located, is capable of determining the electrolyte content during fuel cell operation by measuring the electrical resistance between the wires. The conduit wicks electrolyte into its pores to a content similar to that of the electrolyte reservoir plate. This electrolyte establishes electrical contact between the wires such that the measure of the electrical resistance between the wires is related to the electrolyte content of the electrolyte reservoir plate.

Abstract: Cabinet structure has interconnected side, top and back panels, and base structure connected to the side panels, all with interengaging bevelled edge surfaces. A recess is formed in one bevelled surface and extends outwardly to define an opening on an outer corner edge of the cabinet structure. A coupling member has a rectangular tab inserted in the opening for coupling to auxiliary structure. The base structure is a channel rail receiving a plate sliding longitudinally of the rail from a retracted position to an extended position for engaging in the rail of said similar structure. Sliding drawer suspensions have anti-tilt mechanisms interconnected by an actuating bar which passes through the top panel of the lower of two stacked cabinet structures. The bar is releasably connected to each anti-tilt mechanism to allow assembly and disassembly of the stack.