distribution (Fig. 9b and c). The maximum mean reaction rate of SR
without CO2 addition is 0.063 kmol m3 s1 which develops at O/
C = 1.4. Adding CO2 in the feed gas abates the SR reaction, and the
O/C ratio of the maximum mean reaction rate shifts rightward. The
maximum mean reaction rate of DR is located at O/C = 1, regardless
of the CO2/O2 ratio. This implies, in turn, that the optimum
condition for DR merely depends on the O/C ratio rather than on
the CO2/O2 ratio.
The distributions of CH4 conversion shown in Fig. 10a indicates
that the conversion is higher when the O/C ratio is higher. This is
owing to the higher maximum temperature and more methane
combustion involved in the catalyst bed, as shown in Fig. 10b.
When the O/C ratio is lower than 0.8, the influence of CO2 addition