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In step with population growth and industrial advance, global demand for energy has risen inexorably and the major sources of energy are fossil fuels (coal, oil, and natural gas). These fuels are non-renewable and will, one day, be exhausted. Moreover, hydrocarbon fuels produce massive emission of greenhouse gases that are considered to be the main reason of the climate change. 1 In comparison, hydrogen is a promising fuel for the future by virtue of its high energy density2 and its clean cold combustion product in fuel cells3. However, hydrogen is not a primary energy source, but it is instead an energy carrier and it must be manufactured from feedstocks that contain hydrogen compounds. The main methods of producing hydrogen are: Electrolysis4, natural gas reforming5 and gasification of coal6 and biomass7. An overview of the various feedstocks and process technologies for hydrogen production is presented in Figure 1-1.