For higher aliphatic feedstock the addition of alkali

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Unformatted text preview: rO2-Al2O3 or Al2O3 containing rare earth metal oxides [17]. For higher aliphatic feedstock the addition of alkali metals oxides to the catalyst is necessary to prevent excessive carbon formation. However, the reduction of the catalytic activity by alkali metal oxides and the continuous removal of the alkali metals with time-on-stream are major problems [17, 18]. 1.3.2. Other processes for syngas production The other major pathway for the production of syngas and hydrogen is the non-catalytic partial oxidation of fossil fuels often also referred to as gasification [10, 11]. A key advantage of this process is that it accepts all sorts of refinery feedstock including such as heavy distillation fractions and petroleum coke that are not suitable for steam reforming. Furthermore is it an exothermic reaction, but as it is not a catalysed process high reaction temperatures are needed (~1300°C). The large amounts of coke produced in the process have to be regularly removed from the reactor walls. An alternative approach to the non-catalysed partial oxidation and the steam reforming is the autothermal reforming [10, 11]. In this process the exothermic non-catalytic partial oxidation is combined with the endothermic steam reforming. The advantage is that it uses the energy surplus of the partial oxidation reaction to run the steam reforming, using only a single reactor and no outer heating. Typically, in the top of the reactor the non-catalytic partial oxidation reaction takes place providing the heat for the endothermic steam reaction over Ni based catalyst placed downstream the reactor. 27 1. Introduction The production of hydrogen by CO2 reforming has no importance because of the high energy input needed and the low H2/CO ratio. However the low H2/CO ratio available in this process can be beneficial for the Fischer-Tropsch synthesis of products with a lower H/C ratio like olefins and oxygenated products [17, 77, 80, 81, 82, 83, 84, 85]. CO2 reforming has found industrial application in the reduction of iron ore (Fe2O3) by synthesis gas, because CO2 reforming yields syngas...
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