Reformer installation with heat shield

#The invention relates to a reformer installation for generating a hydrogen-rich product gas from a hydrocarbon-containing fluid. The reformer installation includes a housing having at least one reformer zone, which is disposed in an interior of the housing, and at least one feed line. A reformer installation of that type is used, for example, to provide hydrogen for operating a fuel cell in the automotive industry.

#Fuel cells for supplying energy to electrically driven motor vehicles are currently the subject of intensive research work. The fuel for the fuel cell is hydrogen. The question arises, especially for use in mobile applications, as to whether the hydrogen should be carried along and used directly in the vehicle or whether it should be stored in an indirect form in what are known as hydrogen carriers such as, for example, methanol, gasoline, diesel fuel, etc., and only converted into hydrogen in the vehicle itself. Since there currently is no suitable infrastructure for refueling motor vehicles with liquid hydrogen and since the storage of the hydrogen also presents problems, the reforming of hydrocarbons to obtain hydrogen on board the motor vehicle is currently preferred.

#The term reforming is used to cover a range of processes for the production of hydrogen-rich gases, known as reformates. The use of catalysts in the reformer allows the process to be accelerated and to be controlled better. The most important catalytic processes are explained briefly below.

#FIG. 1 is a fragmentary, diagrammatic, perspective view of an embodiment of a reformer installation according to the invention; and

#FIG. 2 is a partly broken-away and partly sectional perspective view of a further embodiment of the reformer installation according to the invention, having a honeycomb body.

#Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic and perspective illustration of a reformer installation 1 for generating a hydrogen-rich product gas from a hydrocarbon-containing fluid. The reformer installation 1 includes a housing 2 having first, second and third reformer zones 3, 4, 5 which are disposed in an interior 6 of the housing. In order to provide thermal insulation, the reformer installation 1 has a heat shield 8 which is constructed in such a manner that it takes at least 8 hours for the operating temperature in the reformer zones 3, 4, 5 to drop by 50%, and that it preferably takes at least 8 hours for the operating temperature in the reformer zones 3, 4, 5 to drop by 20%. The heat shield 8 is additionally constructed with a heat accumulator or heat storage device 15, which is preferably made from a phase change material. The first reformer zone 3 is used in this case for partial oxidation, the second reformer zone 4 for steam reforming of the hydrocarbon-containing fluid and the third reformer zone 5 for catalytic purification of the product gas. Each reformer zone 3, 4, 5 has a honeycomb body 10, so that the fluid which is to be reformed flows through this honeycomb body 10 in a flow direction 19. The heat shield has a higher thermal conductivity in the third reformer zone 5 than in the second reformer zone 4 and the heat shield 8 has a lower thermal conductivity in the third reformer zone 5 than in the first reformer zone 3. Alternatively, different heat shields may be provided in the different zones to provide the thermal conductivities mentioned above.

#The housing 2 has a feed line 7, which is disposed along an extension of an axis 17, through which the hydrocarbon-containing fluid can be introduced into the reformer installation 1. The feed line 7 has an electric heater 9 which, by way of example, is provided to prevent rapid cooling. The heat shield 8 also has an electric heater 9. Two further feed lines 7 are respectively disposed at a start of the second reformer zone 4 and the third reformer zone 5, as seen in the flow direction 19. The further feed lines 7 are used, for example, to supply steam or an oxygen-containing gas for reforming or oxidizing the hydrocarbon-containing fluid. The feed lines 7 may also have heat shields, preferably with heat storage devices or accumulators, in a manner similar to elements 8 and 15.

#A fuel cell 14, to which the hydrogen-rich product gas is supplied, is disposed downstream of the reformer installation 1, as seen in the flow direction 19. The fuel cell 14 is used, in particular, to drive an electric motor vehicle. Exhaust gas produced in the process is discharged to the environment, if appropriate following a further purification stage.