Currently, hydrogen is mainly produced from natural gas by
three different chemical processes: steam reforming, partial
oxidation, and autothermal reforming [1–7]. Steam reforming
involves the endothermic conversion of methane and water vapor
into hydrogen and carbon monoxide. The high temperature
requirement (700 to 1000 8C) is often achieved by the combustion
of some of the methane feed gas. Partial oxidation of natural gas, on
the other hand, is the process whereby partial combustion of
methane with oxygen gas yields carbon monoxide and hydrogen.
Heat is produced in an exothermic reaction; therefore, a more
compact design is possible because external heating of the reactor
is not required. Finally, autothermal reforming is a combination of
both steam reforming and partial oxidation. The total reaction is
exothermic; hence, heat is released. The outlet temperature of the
reactor is in the range of 600 to 900 8C