Abstract
Fuel processing is the conversion of fossil and regenerative fuels to hydrogen-containing gas mixtures. The chemical conversion is performed in most cases in the gas phase, normally heterogeneously catalyzed in the presence of a solid catalyst. The first step of the conversion procedure is named reforming. It has been established in large-scale industrial processes for many decades. The industrial applications most commonly use natural gas as feedstock. The product of the natural gas reforming process is synthesis gas, a mixture of carbon monoxide and hydrogen, which is then used for numerous processes in large-scale chemical production which are not subject of this section but rather the technology, which provides a hydrogen-containing gas mixture, named reformate, which is a feed suitable for a fuel cell. The fuel cell then converts hydrogen to electrical energy. Depending on the fuel cell type, removal of carbon monoxide might be required, which is achieved by water-gas shift and preferential oxidation reactions performed downstream the reformer. The reactor types suitable for mobile and decentralized applications are, apart from conventional fixed-bed reactors, ceramic and metallic monoliths, (microchannel) plate heat exchangers, and membrane reactors which allow the combination of membrane separation with the reactions mentioned previously.