摘要:
A methanol reforming catalyst containing passivated copper and zinc oxide and/or alumina can be prepared by (1) precipitating or spray-drying a mixture of catalyst precursor components dissolved or suspended in a diluent in order to form a solid catalyst precursor in the form of powder or granules, (2) calcining and reducing the solid catalyst precursor obtained in stage (1), (3) passivating the reduced catalyst precursor obtained in stage (2) and (4) shaping the passivated catalyst precursor obtained in stage (3) to form the catalyst. A reduction in the volume shrinkage and an increase in the mechanical hardness during operation of the methanol reforming catalyst are achieved by the preparation process.
摘要:
A fuel cell system includes a polymer electrolyte membrane fuel cell unit having a cooling circuit and an evaporator having at least one evaporation chamber for evaporation of a medium in the fuel cell system and at least one heat-transfer chamber which thermally communicates with the evaporation chamber. The heat-transfer chamber is a part of the cooling circuit of the fuel cell unit.
摘要:
A system for the water vapor reforming of a hydrocarbon includes an evaporator, a prereforming unit, a main reformer, a CO removal unit and at least one catalytic burner unit. A first burner unit is in a thermal contact with the evaporator and a second burner unit is in a thermal contact with the main reformer, and the prereforming unit is in a thermal contact with the CO removal unit by way of one heat conducting separating medium. In addition, the outlet of the CO removal unit is connected with the inlet of the at least one burner unit. During a cold start, a heating-up operation is carried out during which first the two burner units are activated with an external feeding of hydrogen or hydrocarbon, and the reforming operation is started with a hydrocarbon fraction that is lower than in the normal operation. The resulting reformate gas, instead of the externally fed hydrogen or hydrocarbon, is introduced as fuel into the burner units.
摘要:
A system for supplying an evaporated and/or superheated hydrocarbon or hydrocarbon/water mixture to at least two components of a gas generation system of a fuel cell system, in particular to at least two stages of a multi-stage reforming process. In one embodiment, the system contains at least two heat exchangers, each of which contains a media-side area and an area that serves to input thermal energy. Furthermore, each of the heat exchangers is connected to least one of the components of the gas generation system and the two heat exchangers are connected to each other. In an alternate embodiment, the system contains one heat exchanger, the media-side area of which is connected to a valve device, which distributes the evaporated and/or superheated mixture to at least two conduits, each of which leads to one of the two components of the gas generation system.
摘要:
A methanol reforming catalyst containing passivated copper and zinc oxide and/or alumina can be prepared by (1) precipitating or spray-drying a mixture of catalyst precursor components dissolved or suspended in a diluent in order to form a solid catalyst precursor in the form of powder or granules, (2) calcining and reducing the solid catalyst precursor obtained in stage (1), (3) passivating the reduced catalyst precursor obtained in stage (2) and (4) shaping the passivated catalyst precursor obtained in stage (3) to form the catalyst. A reduction in the volume shrinkage and an increase in the mechanical hardness during operation of the methanol reforming catalyst are achieved by the preparation process.
摘要:
A gas generating system for a fuel cell system as well as to a method of operating same. In order to provide hydrogen-containing combustible gas as rapidly as possible and to reduce the exhaust gas emissions, for the start of the operation of the gas generating system, at least one catalytic burner is started and the generated heat is used for evaporating a combustion agent and/or water and for the heating-up of an additionally connected partial reforming unit or partial oxidation stage in order to generate a hydrogen-containing gas for the fuel cell unit by reforming or partial oxidation.
摘要:
A heat exchanger has a plurality of fluidically parallel first layers which define first heat exchanger ducts through which a first medium is capable of flowing, and in each case has a second layer between the two first layers. The respective second layer is in thermal contact with the two adjacent first layers and defines at least one second heat exchanger duct through which a second medium is capable of flowing in parallel. The respective second layer comprises two fluidically parallel layer plies. A controllable supply of the second medium to the one and/or the other layer ply in each case is provided. Such a heat exchanger can be used, in particular, as an evaporator with an integrated starting and main evaporator part, and particularly as an evaporator in a reforming plant of a fuel-cell vehicle.
摘要:
A fuel cell system, which may include a fuel processing subsystem for converting hydrocarbons into a hydrogen-rich gas, is designed so that at least some of the components of the fuel cell system are contained inside at least one housing. The housing contains a recombiner to convert hydrogen and oxygen into water. The housing may also contain a temperature sensor in the vicinity of the recombiner.
摘要:
A method for operating a gas generation device, for example, for a fuel cell system, having at least two gas generation units through which a starting-material stream flows in series. The two gas generating units have a first and second rated power Prated—1, Prated—2 and a first and second predetermined operating temperature Trated—1, Trated—2, and the first gas generation unit has a lower thermal mass than the second gas generation unit. During a starting phase only the first gas generation unit is operated, with a power Pstart—1>Prated—1. After the end of the starting phase at least the second gas generation unit is operated.
摘要:
A system for generating hydrogen-rich gas has a reformer for catalytic water vapor reforming of a water vapor/fuel mixture by an input supply of thermal energy, and a CO oxidation stage for removing carbon monoxide from the hydrogen-rich gas while emitting heat, with the reformer and the CO oxidation stage being thermally coupled. An oxygen quantity fed to the CO oxidation stage is adjusted as a function of the gas temperature in or at the output of the reformer/oxidation stage. This can take place by an automatic (feedback) control, a combination of open loop control and automatic control or by an adaptive characteristic diagram.