Since homogeneous reactions can be excluded at the low temperatures of interest for this study all
reactions are related to catalytic activity at the inner walls of the reactor. A model can be defined based on
the Langmuir-Hishelwood approach coupled with the classical Arrhenius expression for the rate
coefficients. By performing a range of experiments the parameters to be used in the model for the reactions in Table 3 were produced. In the temperature range of 150 °C to 450 °C and at atmospheric
pressure the accuracy of the calculated molar flows is about 10 % in the case of carbon-containing species
and substantially better in the case of carbon-free species. The reason for this is the formation of carboncontaining
deposits on the reactor’s inner surface. Consequently, the history of the reactor can have an
influence on auto-oxidation effects which the presented model could not take into account. Under the
assumption of first order kinetics the model can be applied for simulation of auto-oxidation effects at high
pressure.