  A one-dimensional and stationary reactor model is presented to describe the
catalytic conversion of a gaseous hydrocarbon fuel with air and steam to
synthesis gas by autothermal reforming (ATR) and catalytic partial oxidation
(CPO). The model defines two subsequent sections in the reactor, namely an
upstream oxidation section, and a downstream reforming section. In the
oxidation section all of the oxygen is converted, with partial conversion of
the fuel. An empirical fuel utilization ratio is used to quantify which part of
the fuel is converted in the oxidation section as function of the relative
flows of air and steam. In the oxidation section, the gas temperature rapidly
increases toward the toptemperature at the intersection with the reforming
section. In this section the temperature decreases while the fuel is further
converted with water and CO2 as oxidant. For methane as fuel, simulation
results are presented and compared with experiments. For multicomponent fuels
such as natural gas and naphtha, it is described how the two-section model can
be applied.
