Abstract:
Fuel cell system comprising at least one fuel cell which includes an anode compartment and a cathode compartment which are separated from one another by a proton-conducting membrane, further comprising a cathode feeder for delivering oxygen-containing gas to the cathode compartment, an anode feeder for delivering a liquid coolant/fuel mixture to the anode compartment, the anode compartment being disposed in an anode circuit which comprises a gas separator and a pump, and cooling of the coolant/fuel mixture circulating in the anode circuit is effected by the fuel cell which is designed for operation involving water break-through from the anode compartment into the cathode compartment. The evaporation cooling thus achieved in the fuel cell results in cooling of the coolant/fuel mixture at a steady-state operating temperature which is established in the fuel cell as a function of the membrane properties and the speed of the pump, thus obviating the need for any additional cooler in the anode circuit itself.
Abstract:
In a method and apparatus for selective catalytic oxidation of carbon monoxide, the gas mixture and an additionally added oxidizing gas are conducted through a reactor containing the catalyst. Oxidizing gas is added at several points along the mixed gas flow path with a controlled or regulated through flow volume. The mixed gas stream is cooled passively by static mixing structures located in the inlet area of the CO-oxidation reactor. By controlling exothermal CO oxidation along the reactor path, a very variable process guidance is provided, that can be adjusted to individual situations.
Abstract:
A reforming reactor system for water vapor reforming of methanol in fuel-cell operated motor vehicles has a reactor unit with a catalyst-filled reaction space and a particle filter which is arranged in a reformate gas pipe downstream of the reactor unit. The catalyst material is carried in the reaction space by a sieve below which a metallic nonwoven for catching sieved-out fragments and dust particles of the catalyst fill is situated. The particle filter contains a spun steel wool netting and/or several filter steps serially connected behind one another. The particle filter may be arranged to be exchangeable without interrupting the operation of the system. Specifically, a particle filter which has a filter body which can be changed in a gas-tight manner transversely to the gas flow and/or a cyclone filter can be used which has a closing device for the purpose of an emptying of a particle collecting pot which does not interrupt the operation.
Abstract:
A moisture exchange module includes a bundle of moisture-permeable hollow fiber membranes. It is provided with a feedline for supplying a gas stream that flows through the hollow fiber membranes in an inner flow. According to the present invention, a separating device for separating out liquid particles from the gas flow are provided in the region between the feedline and the bundle of hollow fiber membranes. The separating device may have the form of a groove and are arranged in such a way that the gas flow is guided in such a manner that the centrifugal force assists movement of the liquid particles towards the separating device. The moisture exchange module preferably forms part of a fuel cell system to humidify feed air for the fuel cell system.
Abstract:
A moisture exchange module includes a bundle of moisture-permeable hollow fiber membranes through which a first gas stream can flow. The bundle of hollow fiber membranes is arranged in a housing, the housing being provided with line elements for supplying and discharging a second gas stream, which flows around the hollow fiber membranes. Between the bundle of hollow fiber membranes and the housing there is at least one flow space, which extends over at least approximately the entire length of that region of the bundle of hollow fiber membranes through which the first gas stream can flow. The at least one flow space surrounds only a small part of the circumference of the bundle of hollow fiber membranes, so that ultimately a moisture exchange operated in cross-current mode is formed. This can preferably be used for the humidification of feed air for fuel cell systems.
Abstract:
A gas generation system includes a reservoir for a reactant, a compressor configured to pressurize the reactant in the reservoir using an operating medium delivered into the reservoir, a gas generation component fed with the reactant using a reactant feed line, and a metering element disposed in the reactant feed line between the reservoir and the gas generation component. In addition, a method for operating a gas generation system includes controlling the delivery of compressed operating medium so as to maintain a pressure in the reservoir at a level corresponding to a pressure of the reactant downstream of the reservoir and metering the reactant in a feed line between the reservoir and the gas generation component.
Abstract:
Fuel cell system has an anode chamber and a cathode chamber separated from one another by a proton-conducting membrane. A cathode supply line supplies gas containing oxygen to the cathode chamber, and an anode supply line supplies a liquid coolant/fuel mixture to the anode chamber. The anode chamber is located in an anode circuit that includes a gas separator and a pump, and with a cooler and a water separator being located in the separated gas flow from the gas separator in the flow direction. According to the invention, the anode circuit has an operating pressure of at least 2.5 bars. The cooler is also cooled by a medium at ambient temperature.
Abstract:
A process for operating a system for water vapor reforming of methanol includes a mixture preparation step for preparing a water vapor/methanol mixture from water and methanol, which mixture is subsequently introduced into a reforming reactor in a quantity which depends on the load condition of the system. According to the invention, the water vapor/methanol mixture ratio of the water vapor/methanol mixture introduced into the reforming reactor is maintained at a predeterminable desired value unaffected by short-term load changing operations, to avoid undesirable short-term increases of the CO-concentration in the reformate.
Abstract:
A membrane module for hydrogen separation includes a stack of flat membrane packs disposed adjacent one another so as not to exert a force on one another and a rotationally symmetrical pressure shell enclosing the stack of flat membrane packs. A feed space for a reformate gas is disposed between every two membrane packs in the stack. Each membrane pack has a pair of membrane assemblies and a support structure disposed therebetween and each membrane assembly includes a hydrogen-selective flat membrane supported by at least one membrane frame.
Abstract:
A moisture exchange module includes a bundle of moisture-permeable hollow fibre membranes. It is provided with a feedline for supplying a gas stream that flows through the hollow fibre membranes in an inner flow. According to the present invention, a separating device for separating out liquid particles from the gas flow are provided in the region between the feedline and the bundle of hollow fibre membranes. The separating device may have the form of a groove and are arranged in such a way that the gas flow is guided in such a manner that the centrifugal force assists movement of the liquid particles towards the separating device. The moisture exchange module preferably forms part of a fuel cell system to humidify feed air for the fuel cell system.